how dry mixtures can be separated? - free divorce advice

how dry mixtures can be separated? - free divorce advice

Answer: Mixtures are all able to be separated by exploiting some physical property. No chemical changes need be involved, so the substances will retain their chemical identity throughout the separation process. An example which could be separated by hand might be a dry mixture of salt and sand.

Heterogeneous Mixtures A heterogeneous mixture is a mixture of two or more chemical substances (elements or compounds), where the different components can be visually distinguished and easily separated by physical means.

The method in which substances in a mixture can be separated by just picking them out with the help of hand from the mixture is known as hand-picking method. It is one of the various methods which are carried out in dry conditions.

To separate sand and salt, we dissolve the mixture in water and then filter it. In this way salt get dissolved in water while sand we get as residue. Thus, we can say handpicking is used for separating slightly larger sized impurities such as pieces of dirt, stones, husk from wheat, rice, pulses etc.

Recycling centres use magnetic separation often to separate components from recycling, isolate metals, and purify ores. Overhead magnets, magnetic pulleys, and the magnetic drums were the methods used in the recycling industry. Magnetic separation is also useful in mining iron as it is attracted to a magnet.

The working principle of magnetic separation is that materials which is going to be elected bearing the force of magnetic and other mechanical (such as gravity, centrifugal force, friction, medium resistance, etc.) together, in the sorting space of the magnetic separator.

The hydraulic separation method of concentration of ore is based on the difference in the specific gravities of the metallic ore and gangue particles. Generally, metal ores are heavier than the gangue particles. The hydraulic separation method uses this property for the concentration of the ore.

Answer: Recycling centres use magnetic separation often to separate components from recycling, isolate metals, and purify ores. Magnetic separation is also useful in mining iron as it is attracted to a magnet.

Wrap a magnet in plastic lunch wrap and move it through the mixture of the three solids. The iron filings will stick to the magnet. The filings can be removed by unwrapping the plastic from the magnet carefully! Mix the remaining salt and sand in water and stir.

How to separate gravel, sand and sugar??? The sugar would dissolve in water. You could the pour off the solution and wash remaining sand bit more water. Heat the water to evaporate the sugar,and the two are separated.

*Use magnet to remove iron filings (magnetic attraction) *Add water to remaining sugar/sand to dissolve sugar (solubility of sugar). *Pour solution through filter to remove sand (solid). *Heat or allow water to evaporate to remove the water sugar remains (solid).

The sand is insoluble, so it will remain visible. Curl a piece of filter paper into a cone shape and place it in a filter funnel. Pour the mixture through the filter funnel into a crucible or evaporating basin. The filter paper will hold back the sand and only allow the salt solution to pass through it.

Answer. decanted out or filtered and the residue containing sand and rice is dried . The dry mixture of sand and rice grains is sieved to separate them rice having bigger sized grains remains on the sieve whereas sand falls down. The filtrate is distilled to get water and salt remains as residue in the flask.

Gravity separation is the most widely used method for oil emulsion separation. The elements in the well stream such as oil and water have different gravities. The density differences allow water to separate by gravity. With enough time in a non-turbulent state, the differing specific gravities will naturally separate.

which type of mixture can be separated using distillation?

which type of mixture can be separated using distillation?

Additionally, which different substances can be separated from each other by method of distillation? Simple distillation is used to separate salt from seawater, to separate sugar from water and to separate ethanol from water in the production of hard liquor.

Homogenous mixtures also called solutions can be separated into the constituent substances by distillation if there is a difference in the concentration of the constituent substances in the gaseous phase. In cases where this does not happen, distillation cannot be used as a means of separation.

separation of mixtures - different methods, examples and faq

separation of mixtures - different methods, examples and faq

In chemistry, the material is made by the physical combination between two similar or different compounds that are mixed together in the form of a solution, colloids, and suspensions. The identities of such compounds are also retained. This is known as a mixture. But, they do not react chemically and are not certainly in a definite ratio. The various components from which mixture is formed have their own physical properties. There are two types of a mixture such as homogeneous and heterogeneous.

A separating funnel is mostly used to segregate or separate the mixture's components between two immiscible liquid phases. The mainly aqueous phase and organic solvents are the two immiscible liquid phases found in this method respectively. The mechanism of separation depends upon the unequal density of the liquids. The liquid particles with more density are responsible for forming the lower layer and the upper layer is formed by the liquid having lesser density. This technique is used to separate oil and water.

The separation technique used to separate the mixture components by passing it in the suspension or solution or as a vapor over a medium in which the mixture constitutes or components move at different rates. This technique is dependent on the various properties of compounds present in two phases i.e mobile and stationary phase.

The technique involves dissolving the sample in a specific solvent known as a mobile phase which may be liquid or gas. This specific solvent is then passed over another phase present called a stationary phase. The separation is based upon different speeds at which different components of a mixture travels.

Evaporation is a method used to separate either homogeneous mixture usually two dissolved salts or a solution consisting of soluble solid and a solvent. The process typically involves heating of the solution until the organic solvent evaporates and no liquid remains behind as it turns into gas and leaves behind the solid components.

An effective method used to separate a mixture that consists of two or more, pure or miscible liquids are known as distillation. It is a purification process in which the components of the liquid mixture are first vaporized and then condensed followed by isolation. In simple distillation, when the mixture is heated then the most volatile component vaporizes first at a lower temperature. The vapor moves through a cooled tube (condenser) and is collected after it gets condensate into a liquid state.

Fraction distillation is a technique used to separate a mixture that comprises two miscible liquids. The process implicates the heating of a liquid up to its boiling point. But, the difference in the boiling points of both the liquid should be less than 25K.

Centrifugation is a technique used for the separation of tiny solid particles from a liquid that can easily pass through a filter paper. Centrifugation is used for carrying out the separation of these insoluble particles where normal filtration fails to work well. The centrifugation depends upon the viscosity of the medium, speed of rotation, shape, size, and density of the particle. This technique is based on the principle that lighter particles stay at the top and heavier or denser particles are forced to move at the bottom when spun rapidly. The apparatus used for the centrifugation technique is called a centrifuge. The centrifuge mainly includes a centrifuge tube holder called rotary. It holds balanced centrifuge tubes that contain an equal amount of solid-liquid mixtures.

Separation of the mixture is important so that the desired composition can be obtained from the mixture. It also helps in a better understanding of the components and how they are contributing to the chemical and physical properties of the resulting mixture.

Sedimentation:- It is the method of separating a mixture containing liquid in which heavier impurities in the form of solid are present to settle down in the bottom of the container containing the mixture.

Magnetic Separation:- If one of the components in the mixture which needs to be separated has some magnetic properties then this method is quite applicable as strong magnets are used to separate the magnetic components.

how can mixtures be separated?

how can mixtures be separated?

Below are some common separation methods: Paper Chromatography. This method is often used in the food industry. Filtration. This is a more common method of separating an insoluble solid from a liquid. Evaporation. Simple distillation. Fractional distillation.

Secondly, what are the 6 methods of separating mixtures? A: There are six ways to separate mixtures including sedimentation, decantation, filtration, evaporation, crystallization and distillation. Mixtures are made up of both solids and liquids. Mixtures that contain only solids must be separated through sublimation, extraction, magnetic separation or chromatography.

mixtures can be separated using various separation methods such filtration,separating funnel,sublimation,simple distillation and paper chromatography. The methods stated above are all physical methods.

Explanation: Filtration works best when the solute isn't dissolve in the solvent. For instance, sand and water can be seperate through filtration as both compounds do not dissolve with each other. However, sugar and water would not be seperated through filtration as they dissolve with each other.

Terms in this set (8) Distillation. separation by boiling point differences. Floatation. separation of solids by density different. Chromatography. separation by inner molecular attractions. Magnetism. Filtration. Extraction. Crystallization. Mechanical Separation.

Summary Mixtures can be separated using a variety of techniques. Chromatography involves solvent separation on a solid medium. Distillation takes advantage of differences in boiling points. Evaporation removes a liquid from a solution to leave a solid material. Filtration separates solids of different sizes.

Separating immiscible liquids is done simply using a separating funnel. The two liquids are put into the funnel and are left for a short time to settle out and form two layers. The tap of the funnel is opened and the bottom liquid is allowed to run. The two liquids are now separate.

The substances in a mixture are separated by the differences in their physical properties, such as their particle size. The more different the properties are, the easier it is to separate the substances. Tea leaves do not dissolve in water, so you can use a strainer to FILTER them.

Separating immiscible liquids is done simply using a separating funnel. The two liquids are put into the funnel and are left for a short time to settle out and form two layers. The tap of the funnel is opened and the bottom liquid is allowed to run. The two liquids are now separate.

Separation of Mixtures. Mixtures are all able to be separated by exploiting some physical property. No chemical changes need be involved, so the substances will retain their chemical identity throughout the separation process. An example which could be separated by hand might be a dry mixture of salt and sand.

A homogeneous mixture in which there is both a solute and solvent present is also a solution. Mixtures can have any amounts of ingredients. Mixtures are unlike chemical compounds, because: The substances in a mixture can be separated using physical methods such as filtration, freezing, and distillation.

Evaporation. Evaporation is a technique used to separate out homogeneous mixtures where there is one or more dissolved salts. The method drives off the liquid components from the solid components. The process typically involves heating the mixture until no more liquid remains.

It is easy to separate sand and water by filtering the mixture. Salt can be separated from a solution through evaporation. The water can also be recovered as well as the salt if the water vapour is trapped and cooled to condense the water vapour back into a liquid. This process is called distillation.

A solution is a homogeneous mixture of two or more substances. A solution may exist in any phase. A solution consists of a solute and a solvent. The solute is the substance that is dissolved in the solvent. For example, in a saline solution, salt is the solute dissolved in water as the solvent.

Use gravity to separate your oil and water emulsion. Centrifuge the two substances together. The heavier liquid will reach the bottom first and stay there, while the lighter of the two will remain in a layer on the top.

The water (the substance) that passes through the filter paper is called the filtrate. If your mixture is a solution, such as salty water, then filtering will not separate the salt from the water. Instead, by heating the soluton the solvent (water) evaporates leaving the solid (salt) behind.

No a sugar and a salt dissolves in water and forms a homogenous mixture that can't be separated by filteration alone .. And you get salt settel down on bottom . Here you can use FILTRATION PROCESS to get salt seprated .. now boil the rest of solution and you get sugar when alchol evaporates .

Lemonade is a special type of mixture called a solution. The ingredients in a solution cannot be separated by hand because of changes in the ingredients' physical properties. But evaporation can be used to separate some solutions. For example, if you heat a solution of sugar water for a while, the water will evaporate.

magnetic separator - an overview | sciencedirect topics

magnetic separator - an overview | sciencedirect topics

Magnetic separators use rare-earth permanent magnets to generate complex flux patterns with huge spatial fluctuations (102 to 105 Tm1) for separating ferrous and nonferrous materials based on their different magnetic susceptibilities.

Batch magnetic separators are usually made from strong rare-earth permanent magnets embedded in disinfectant-proof material. The racks are designed to hold various sizes and numbers of tubes. Some of the separators have a removable magnet plate to facilitate easy washing of magnetic particles (Figure 1). Test tube magnetic separators enable separation of magnetic particles from volumes ranging between about 5L and 50mL. It is also possible to separate cells from the wells of standard microtitration plates. Magnetic complexes from larger volumes of suspensions (up to approximately 5001000mL) can be separated using flat magnetic separators. More sophisticated magnetic separators are available, e.g. those based on the quadrupole and hexapole magnetic configuration.

Figure 1. (See Colour Plate 63). Example of a magnetic separator (Dynal MPC-M) for work with microcentrifuge tubes of the Eppendorf type, with a removable magnet plate to facilitate easy washing of magnetic particles. Courtesy of Dynal, Oslo, Norway.

As magnetic separators progress toward larger capacity, higher efficiency, and lower operating costs, some subeconomic iron ores have been utilized in recent years. For example, magnetite iron ore containing only about 4% Fe (beach sands or ancient beach sands) to 15% Fe (iron ore formations) and oxidized iron ore of only about 10% Fe (previously mine waste) to 20% Fe (oxidized iron ore formations) are reported to be utilized. They are first crushed and the coarse particles pretreated using roll magnetic separators. The magnetic product of roll magnetic separators may reach 2540% Fe and then is fed to mineral processing plants.

where mpap is the inertial force and ap the acceleration of the particle. Fi are all the forces that may be present in a magnetic separator, such as the magnetic force, force of gravity, hydrodynamic drag, centrifugal force, the friction force, surface forces, magnetic dipolar forces, and electrostatic forces among the particles, and others.

Workable models of particle motion in a magnetic separator and material separation must be developed separately for individual types of magnetic separators. The situation is complicated by the fact that many branches of magnetic separation, such as separation by suspended magnets, magnetic pulleys, or wet low-intensity drum magnetic separators still constitute highly empirical technology. Hesitant steps have been taken to develop theoretical models of dry separation in roll and drum magnetic separators. Alternatively, open-gradient magnetic separation, magnetic flocculation of weakly magnetic particles, and wet high-gradient magnetic separation (HGMS) have received considerable theoretical attention. A notable number of papers dealing with the problem of particle capture in HGMS led to an understanding of the interaction between a particle and a matrix element. However, completely general treatment of the magnetostatic and hydrodynamic behavior of an assembly of the material particles in a system of matrix elements, in the presence of a strong magnetic field, is a theoretical problem of considerable complexity which has not been completed, yet. Detailed description of particle behavior in various magnetic separators can be found in monographs by Gerber and Birss (1983) and Svoboda (1987, 2004).

This paper presents preliminary results using the Magnetic Micro-Particle Separator, (MM-PS, patent pending) which was conceived for high throughput isothermal and isobaric separation of nanometer (nm) sized iron catalyst particles from Fischer-Tropsch wax at 260 oC. Using magnetic fields up to 2,000 gauss, F-T wax with 0.30.5 wt% solids was produced from 25 wt% solids F-T slurries at product rates up to 230 kg/min/m2. The upper limit to the filtration rate is unknown at this time. The test flow sheet is given and preliminary results of a scale-up of 50:1 are presented.

Mobile CDW recycling installations have risen in popularity due to the need for traditionally fixed equipment, such as feeders, crushers, magnetic separators and even vibrating screens, used at different locations and at different times. Sometimes it is better, technically and/or economically, to place the CDW recycling plant itself even if in a simplified version at the worksite, instead of transferring the CDW mass to a fixed installation.

Mobile plants will typically be diesel fired, whereas fixed plants are usually connected to the electricity grid and therefore have some inherent advantages, such as higher operation efficiency and lower environmental impacts. Electrical motors, when installed in automobiles, can be as much as three times more efficient than diesel motors (Kendall, 2008). Moreover, electricity may be derived from renewable sources of energy. However, mobile plants reduce material transportation needs, and therefore reduce the noise, dust and gas pollutants typical of diesel motored trucks.

The technology applied in the mobile plant is essentially the same as in fixed plants, though limited to feeders, crushers, vibrating screens and magnetic separators. Its stage of development is similar to that of fixed facilities. Mobile plants are usually mounted on tracks, but there are also some tyre mounted plants commercially available. Their weights vary widely, from 14 up to 215tons, with most of the used equipment between 30 and 50tons (Terex, 2008; Metso, 2009). Capacities can also range from 50 up to 1200ton/h, while remaining fully mobile (Metso, 2012). Usual features include jaw or cone crushers, hydraulic crusher protection mechanisms, flexible variable speed built-in conveyor belts (single or multiple attachable discharge arms), fully automatic discharge adjustment systems, safety and anti-clogging mechanisms, ferrous metals separator (normally as an option), radio control of essential features (e.g. on/off, jaw crusher opening, discharge speed), track mounted extra heavy-duty steel chassis and built-in or optional dust suppression (hose). An example of one of these machines is presented in Fig.9.2, which shows a standard low to medium capacity track mounted model, equipped with a single conveyor belt discharger, magnetic separator and side discharger and a jaw crusher.

Magnetic carriers with immobilized affinity ligand or magnetic particles prepared from a biopolymer exhibiting affinity for the target compound(s) are used to perform the isolation procedure. Magnetic separators are necessary to recover magnetic particles from the system.

Magnetic carriers and adsorbents are commercially available and can also be prepared in the laboratory. Such materials are usually available in the form of magnetic particles prepared from various synthetic polymers, biopolymers or porous glass, or magnetic particles based on inorganic magnetic materials such as surface-modified magnetite can be used. In fact, many of the particles behave like paramagnetic or superparamagnetic ones responding to an external magnetic field, but not interacting themselves in the absence of a magnetic field. This is important due to the fact that magnetic particles can be easily resuspended and remain in suspension for a long time. The diameter of the particles is from ca. 50nm to ca. 10m. Magnetic particles having a diameter larger than ca. 1m can be easily separated using simple magnetic separators, while separation of smaller particles (magnetic colloids with a particle size ranging between tens and hundreds of nanometers) may require the use of high-gradient magnetic separators.

Commercially available magnetic particles can be obtained from a variety of companies. In most cases polystyrene is used as a matrix, but carriers based on cellulose, agarose, silica, porous glass or silanized magnetic particles are also available. Particles with immobilized affinity ligands are available, oligodeoxythymidine, streptavidin, antibodies, protein A and protein G being used most often. Magnetic particles with such immobilized ligands can serve as generic solid phases to which native or modified affinity ligands can be immobilized (e.g. antibodies in the case of immobilized protein A, protein G or secondary antibodies, biotinylated molecules in the case of immobilized streptavidin or adenylated molecules in the case of immobilized oligodeoxythymidine). In exceptional cases, enzyme activity may decrease as a result of usage of magnetic particles with exposed iron oxides. In this case encapsulated microspheres, having an outer layer of pure polymer, are safer. In Table 1 is given a list of companies producing and selling magnetic particles of various types.

In the laboratory, magnetite (or similar magnetic materials such as maghemite or ferrites) particles are usually surface modified by silanization. This process modifies the surface of the inorganic particles so that appropriate function groups become available, which enable easy immobilization of affinity ligands.

Biopolymers such as agarose, chitosan, -carrageenan and alginate can be easily prepared in a magnetic form. In the simplest way, the biopolymer solution is mixed with magnetic particles and after bulk gel formation the magnetic gel formed is broken into fine particles. Alternatively, biopolymer solution containing dispersed magnetite is dropped into a mixed hardening solution or a water-in-oil suspension technique is used to prepare spherical particles. Basically the same procedures can be used to prepare magnetic particles from synthetic polymers such as polyacrylamide or poly(vinylalcohol).

In one of the approaches used, standard affinity chromatography material is post-magnetized by pumping the water-based ferrofluid through the column packed with the sorbent. Magnetic material accumulates within the affinity adsorbent pores thus modifying the chromatography material into magnetic form.

Some affinity ligands (usually general binding ligands) are already immobilized to commercially available carriers (see Table 1). To immobilize other ligands to both commercial and laboratory-made magnetic particles, standard procedures used in affinity chromatography can be employed. Usually functional groups available on the surface of magnetic particles such as COOH, OH or NH2 are used for immobilization; in some cases, magnetic particles are already available in the activated form (e.g. tosyl activated).

Magnetic separators are necessary to separate the magnetic particles from the system. In the simplest approach, a small permanent magnet can be used, but various magnetic separators employing strong rare-earth magnets can be obtained at reasonable prices. Commercial laboratory scale batch magnetic separators are usually made from magnets embedded in disinfectant-proof material. The racks are constructed for separations in Eppendorf microtubes, standard test tubes or centrifugation cuvettes. Some have a removable magnetic plate to facilitate washing of separated magnetic particles (Figure 1). Other types of separators enable separations from the wells of microtitration plates and the flat magnetic separators are useful for separation from larger volumes of suspensions (up to ca. 5001000mL).

Flow-through magnetic separators are usually more expensive and more complicated, and high-gradient magnetic separators (HGMS) are typical examples (Figure 2). Laboratory-scale HGMS are constructed from a column packed with fine magnetic-grade stainless-steel wool or small steel balls placed between the poles of an appropriate magnet. The suspension is pumped through the column, and magnetic particles are retained within the matrix. After removing the column from the magnetic field, the particles are retrieved by flow and usually by gentle vibration of the column.

Figure 2. (See Colour Plate 62). A typical example of laboratory-scale high-gradient magnetic separators. OctoMACS Separator (Miltenyi Biotec, Germany) can be used for simultaneous isolation of mRNA. Courtesy of Miltenyi Biotec, Germany.

MACS, one of the most popular conventional cell isolation methods, has recently been developed in microfluidics to isolate rare cells. Tan and colleagues first introduced micro-magnetic separators for stem cell sorting (Fig.11.24) (Tan et al., 2005). A 3D mixer was integrated in a microfluidic channel to achieve lamination with 180-degree rotations and rapid mixing between cells and magnetic beads. To isolate the target cell from the mixture, magnetic beads conjugated with CD31 antibodies were used to remove CD31+ endothelial cells with an external magnetic field. Up to 90.2% of hMSCs were isolated and recovered. In addition, Souse and colleagues introduced a two-inlet/two-outlet microfluidics device to isolate mouse mESCs using super-paramagnetic particles. To isolate specific embryonic antigen 1 positive (SSEA-1+) mESCs from a heterogeneous population of mESCs, anti-SSEA-1 antibodies were conjugated onto super-paramagnetic beads and mixed with the cell mixture. Once the mixture was injected into the microfluidics channel and the magnetic field was applied, SSEA-1+ mESCs were deviated from the direction of laminar flow according to their magnetic susceptibility and were thus separated from SSEA-1 mESCs.

A great deal of exciting new spectroscopy of nuclei far from stability or with very large Z has been achieved over the last several years when large Ge detector arrays have been coupled to high-transmission magnetic separators. A magnetic separator is a device placed behind the target position which will selectively transport nuclei, produced in a reaction, to its focal plane where they can be detected and identified using a variety of different detectors. Residual nuclei that are not of interest, or scattered beam particles, will not be transmitted through the separator. Very small fractions of the total reaction cross section can be selected using this method. Nuclear structure information is obtained by detecting gamma-rays produced at the target position, in coincidence with recoils detected at the focal plane. One example of the use of this technique is illustrated here.

One of the goals of nuclear physics is to understand the limits of nuclear existence as functions, for example, of angular momentum, isospin, or indeed mass. For example, what are the heaviest nuclei that can exist? For many years now, various models have predicted that an island of superheavy nuclei should exist. However, most models disagree as to the exact proton and neutron numbers categorizing this island and indeed on the extent of the island. Recently, models have predicted that these superheavy nuclei might indeed be deformed. Therefore, it is very relevant to inquire as to what is the structure of the heaviest nuclei accessible to gamma-ray spectroscopy and to ask the simplest type of questions about them, for example, are they spherical or deformed? Unfortunately, the production cross sections for superheavy nuclei are such that, even using very intense beams, only one or two nuclei are produced per week or two. These small numbers are clearly beyond what we can measure with existing gamma-ray facilities. Therefore, we cannot address the spectroscopy of the superheavy elements (yet). However, we can look at the structure of very heavy nuclei lying just below these unattainable regions.

Recently, groups at Argonne National Laboratory in the United States and at the University of Jyvaskyla in Finland carried out tour de force experiments to study the excitation spectrum of 254No(Leino et al., 1999). With Z=102, No is the heaviest nucleus for which gamma-ray spectroscopy has ever been carried out. The gamma-ray spectrum of transitions de-exciting states in 254No is shown inFig. 13. A rotational band structure is clearly visible, indicating that 254No is in fact a deformed nucleus. A very surprising feature of the spectrum is that the rotational band is observed up to very high spins 18 , (an amazing number for such a heavy, fissile nucleus). The existence of a rotational cascade up to spin 18 , well beyond the classical fission barrier limit, indicates that 254No is held together primarily by microscopic shell effects, rather than macroscopic liquid drop binding, as in normal nuclei. Shell effects, for certain favorable proton and neutron numbers and for favorable deformation, can provide an additional 12MeV of binding energy. It is this binding energy, which does not depend strongly on angular momentum, which holds 254No together to such high spin.

FIGURE 13. Spectrum of gamma-rays depopulating excited states in 254No. With Z=102, 254No is the heaviest nucleus for which gamma-ray spectroscopy has ever been accomplished. The gamma-rays are labeled by their transition energies in kilo-electron volts and also by the spin of the state they depopulate. The inserts show the population intensity as a function of spin for the two beam energies, 215 (top) and 219MeV (bottom). More angular momentum is brought into the system at higher beam energies, and this is reflected in the stronger population of higher spin states in the lower spectrum(Leino et al., 1999).

Coalescence separators (Fig. 8.18) are flow-through systems which guarantee a very high degree of separating capacity compared to more simple systems. More sophisticated coalescence separators (coolant cleaners) are equipped with pre filters and magnetic separators to clean the emulsion from floating swarf such as aluminum or other light metal fines as well as from ferromagnetic particles.

The effect of the coalescence principle is based on the flowing together of many droplets to a compact liquid phase (contaminant-oil phase). The coalescence principle is supported by the formation of large surfaces; these are achieved by the arrangement of plate packs or packing elements in a separate tank.

Owing to their large surfaces, a disadvantage must be noted; solids will also adhere to the surfaces. Depending on the contamination of the emulsion, the plate pack or the packing elements must be regularly removed and mechanically cleaned.

separation of mixture : class 6 chemistry lesson - separation of substances

separation of mixture : class 6 chemistry lesson - separation of substances

When two or more than two substances is completely mixed with each other and form uniform mixture is called as homogeneous mixture. It can be solid, liquid and gaseous mixture which is completely mixing with each other. It does not have identical or visible layer in mixture.

name the process by which the components of following mixtures can be separated. - studyrankersonline

name the process by which the components of following mixtures can be separated. - studyrankersonline

(a) FILTRATION :Glass and sugar on dissolving in water and filtering, glass separates out as residue on the filter paper. Filtrate of sugar solution is heated to remove water by evaporation, sugar is collected as crystals.(b) MAGNETIC SEPARATION :With the help of a magnet, iron filings can be separated leaving behind chalk powder.(c) WINNOWING :It separates chaff (lighter) from heavier grains in two different heaps.(d) EVAPORATION :This method is used to separate the components of a homogeneous solid-liquid mixture, like salt from sea water. Sea water is collected in shallow beds and allowed to evaporate in the sun. When all the water is evaporated, salt is left behind.(e) EVAPORATION :Wheat and sugar are put in water in a beaker. Sugar dissolves and mixture is passed through strainer and separated and dried. Sugar is obtained by evaporating sugar solution.(f) SUBLIMATION :Camphor sublimes on heating leaving behind sand.(g) CRYSTALLISATION :Pure sugar is obtained from its solution in water by the process of crystallisation. At first the sugar solution is heated to evaporate Water at a faster speed. When very less of water is left the solution is cooled. On cooling sugar dissolved in it starts separating out in the form of crystals.

what are the ways to separate mixture?

what are the ways to separate mixture?

Likewise, what are the 4 ways to separate mixtures? Summary Mixtures can be separated using a variety of techniques. Chromatography involves solvent separation on a solid medium. Distillation takes advantage of differences in boiling points. Evaporation removes a liquid from a solution to leave a solid material. Filtration separates solids of different sizes.

Below are some common separation methods: Paper Chromatography. This method is often used in the food industry. Filtration. This is a more common method of separating an insoluble solid from a liquid. Evaporation. Simple distillation. Fractional distillation.

Terms in this set (8) Distillation. separation by boiling point differences. Floatation. separation of solids by density different. Chromatography. separation by inner molecular attractions. Magnetism. Filtration. Extraction. Crystallization. Mechanical Separation.

A solution is a homogeneous mixture of two or more substances. A solution may exist in any phase. A solution consists of a solute and a solvent. The solute is the substance that is dissolved in the solvent. For example, in a saline solution, salt is the solute dissolved in water as the solvent.

Use gravity to separate your oil and water emulsion. Centrifuge the two substances together. The heavier liquid will reach the bottom first and stay there, while the lighter of the two will remain in a layer on the top.

If you take a jar and fill it with water, put some 'straightforward' oil on top and shake it, all you need to do to separate the oil and the water is to put the jar on a table and wait. Shortly there will be a layer of oil floating on the surface and all that is left to do is to remove the oil layer.

Separating immiscible liquids is done simply using a separating funnel. The two liquids are put into the funnel and are left for a short time to settle out and form two layers. The tap of the funnel is opened and the bottom liquid is allowed to run. The two liquids are now separate.

A: There are six ways to separate mixtures including sedimentation, decantation, filtration, evaporation, crystallization and distillation. Mixtures are made up of both solids and liquids. Mixtures that contain only solids must be separated through sublimation, extraction, magnetic separation or chromatography.

The substances in a mixture are separated by the differences in their physical properties, such as their particle size. The more different the properties are, the easier it is to separate the substances. Tea leaves do not dissolve in water, so you can use a strainer to FILTER them.

For example, water can be separated from salt solution by simple distillation. This method works because water has a much lower boiling point than salt. When the solution is heated, the water evaporates. It is then cooled and condensed into a separate container.

When sand is added to water it either hangs in the water or forms a layer at the bottom of the container. Sand therefore does not dissolve in water and is insoluble. It is easy to separate sand and water by filtering the mixture. Salt can be separated from a solution through evaporation.

A method of separating a powder mixture, comprising: applying a first external magnetic field to the powder mixture having a first powder that is non-magnetic and a second powder that is non-magnetic in order to magnetize the first powder and leave the second powder in a non-magnetized state; and using a second

Terms in this set (5) Gravity filtration. used to separate mixture that contains an insoluble solid form a liquid (insoluble means it can't dissolve in water and is therefore visible in a liquid)The mixture is pored over a piece of filter paper. Evaporation. Simple distillation. Centrifugation. Magnetic Separation.

Filtering Flute filter paper if necessary. Place filter paper in the funnel. Wet the filter paper using a small amount of the liquid that is the solvent of the mixture being filtered. After the filtrate has been collected, pass a small amount of the wash liquid through the filter paper to wash the residue.

For example, liquid ethanol can be separated from a mixture of ethanol and water by fractional distillation. This method works because the liquids in the mixture have different boiling points. When the mixture is heated, one liquid evaporates before the other.

q8 state what is meant by magnetic separation of two mixture | lido

q8 state what is meant by magnetic separation of two mixture | lido

Magnetization is a technique of attracting magnetic substances. Magnetic separation means separating mixtures of two solids with one part which has magnetic properties. It is based on the difference in magnetic and non-magnetic substances.

"Hello friends welcome politically homework solving session today we'll be looking at the following question. The question says State what is meant by magnetic separation of mixtures explain how Iron particles can be separated from Surfer particles. So in this question, we have to mention a what is meant by the magnetic separation of two mixtures and we have developers explain how Iron particles can be separated from sulfur particles. So basically if we have iron and sulfur which are out with us and we have put satanic. Plain how we can separate these iron from The sulfur now let's look at this question. First. We are going to Define what is meant by magnetic separation. So magnetic separation is magnetization as we all know we need this is the magnet which we can look from the figure out here the this is the magnet So this magnetization is a technique of attracting. Magnetic substances So magnetic separation means it means updating its magnetic suppression is what's up, dating or suppression of two solids? Which one part which has a magnetic properties? So we have actually two solids which are to be separated from each other among the two solid one part is having magnetic properties. It is based on the difference in the magnetic and non-magnetic substance. For example, I have iron and sulfur mixture. Okay, and in this I know that my iron particles get attracted. To magnet Sulfur, it was a non-magnetic substance. So when I take my magnet close to this iron and sulfur picture iron particles get attracted towards the magnet and assess how I can separate iron and sulfur from each other. So, this is how I approach this question. Hope you understood the solution in case if you have any doubts, please feel free to drop a comment below and subscribe to this channel for regular updates. Thank you."

Magnetization is a technique of attracting magnetic substances. Magnetic separation means separating mixtures of two solids with one part which has magnetic properties. It is based on the difference in magnetic and non-magnetic substances.

"Hello friends welcome politically homework solving session today we'll be looking at the following question. The question says State what is meant by magnetic separation of mixtures explain how Iron particles can be separated from Surfer particles. So in this question, we have to mention a what is meant by the magnetic separation of two mixtures and we have developers explain how Iron particles can be separated from sulfur particles. So basically if we have iron and sulfur which are out with us and we have put satanic. Plain how we can separate these iron from The sulfur now let's look at this question. First. We are going to Define what is meant by magnetic separation. So magnetic separation is magnetization as we all know we need this is the magnet which we can look from the figure out here the this is the magnet So this magnetization is a technique of attracting. Magnetic substances So magnetic separation means it means updating its magnetic suppression is what's up, dating or suppression of two solids? Which one part which has a magnetic properties? So we have actually two solids which are to be separated from each other among the two solid one part is having magnetic properties. It is based on the difference in the magnetic and non-magnetic substance. For example, I have iron and sulfur mixture. Okay, and in this I know that my iron particles get attracted. To magnet Sulfur, it was a non-magnetic substance. So when I take my magnet close to this iron and sulfur picture iron particles get attracted towards the magnet and assess how I can separate iron and sulfur from each other. So, this is how I approach this question. Hope you understood the solution in case if you have any doubts, please feel free to drop a comment below and subscribe to this channel for regular updates. Thank you."

summary | separating mixtures | siyavula

summary | separating mixtures | siyavula

'Mixtures' was first introduced in Gr. 6, so learners should already be familiar with these concepts. Learners would have also looked at some of the physical methods of separating different types of mixtures (including hand sorting, sieving, filtration), and this year we will explore some additional methods in more detail (including distillation and chromatography).

In the first section of this chapter, learners will learn how to identify mixtures. One of the central ideas in this section is that the components in a mixture are not chemically joined. They still exist as separate compounds that have not reacted with each other in any way. For that reason, mixtures can be separated using physical methods. Physical methods can not be used to separate elements that are chemically joined.

In order to make this section more interesting you could provide small samples of each of the mixtures discussed and ask learners to draw them, paying close attention to any features that a particular mixture may have. When they are faced with a solution (water and sugar, for instance) they might notice that there are no visible features to draw. This will help establish in their minds that solutions are mixtures where the substances are so intimately mixed (literally on the level of individual particles) that we cannot make out separate substances anymore.

Get your learners to act out the word 'mix'. Learners might make stirring motions with their arms. This exercise may seem trivial but their attention will immediately be focussed (and their learning enhanced) if they are engaged in this way. Using gestures that require learners to move their bodies has been shown to enhance learning even at university level!

Some learners may say no, you need two or more things mixed together to have a mixture. Other learners may answer that it is possible to mix hot water with cold water. Point out that the end result would just be water, and not really a mixture of hot and cold water; once mixed, the water would have the same temperature throughout.

A mixture can contain solids, liquids and/or gases. The components in a mixture are not chemically joined; they are just mixed. That means we do not need to use chemical reactions to separate them. Mixtures can be separated using physical methods alone and that is what this chapter is all about: how to separate mixtures.

This is a revision of the types of mixtures that one can get, which has been done in Gr. 6 Matter and Materials. If you feel your learners have already grasped this, you can go through it briefly by just looking at the different pictures provided and ask learners what types of mixtures they are.

What happens when clay or sand is mixed with water? Would you be able to see through a mixture of clay and water? The mixture of clay or sand with water is muddy. The small clay particles become suspended in the water. This kind of mixture is called a suspension. Suspensions are opaque; that means they are cloudy and we cannot see through them very well.

What happens when sugar is mixed with water? Does the mixture become muddy? Why not? The sugar dissolves in the water and the mixture is called a solution. Solutions are clear; that means we can see through them.

Keep in mind that some mixtures that we expect to be solutions end up being suspensions. A good example is table salt and water that could end up looking cloudy because of the starch (free-flowing agent). In this case it would be better to use pure sea salt. (You could also use this apparent paradox as the basis of an extension activity about what appearances allow us to infer in certain situations.)

Milk is not a single substance, but actually a mixture of two liquids! The one liquid component in milk is water, and the other is fatty oil. The reason milk is opaque is that tiny droplets of the oil is suspended in the water. Can you remember what a mixture is called when a solid is suspended in liquid?

We use milk as an example of a suspension, however, milk is actually more complex since it also contains solutes. It is a great example of a mixture that has both solution and suspension (emulsion) components. Flour or maizena mixed with water also makes a good suspension which settles after some time. This is also a good opportunity to revise the terms solute, solvent and solution, namely the solute (for example sugar) is the substance that is dissolved in the solvent (for example water) to form a solution (for example sugar water).

Are all liquid-liquid mixtures emulsions? (One way to recognise an emulsion is that it is opaque). Are all liquid-liquid mixtures opaque? Can you think of a liquid-liquid mixture that is not an emulsion? Discuss this with your class and give an answer below.

Firstly, no, not all liquid-liquid mixtures are opaque. Secondly, most solutions that learners will be able to think of are essentially solid-liquid mixtures at the fundamental level. It is good enough for learners at this level to offer examples of liquid-liquid mixtures such as 'a mixture of apple juice and water'.

A better example of a liquid-liquid solution is vinegar, which is a mixture of ethanoic acid (acetic acid) - a liquid at room temperature - and water. This example might be a sensible inclusion since it would serve as early introduction to households acids that will feature prominently in the next chapter (Acids and Bases). If learners are given a vinegar sample to draw, it would be better to provide a sample of white vinegar, since it contains less solid matter. Once again they will be confronted with the realisation that the solution does not have visible features. Another opportunity to establish that solutions are mixtures where the substances are so intimately mixed that we cannot make out separate substances anymore.

Solutions are special kinds of mixtures in which the particles are so well mixed that they are not separated from each other. We cannot make out separate substances anymore - everything looks the same when we look with the naked eye.

The particle model of matter will only be dealt with in detail in Gr. 8, but the following kinds of visual representations may aid understanding of abstract concepts. You can draw these on the board with different colours. Learners were exposed to similar images in Gr. 6. However, it is not critical at this stage and you do not need to go into detail. Solutions look glassy/translucent, and the solid particles cannot be seen. The substances cannot be separated by filtration (dealt with later in this chapter).

In a suspension, one of the substance's particles are always clumped together. Sometimes one can even see little globs of oil (in the case of an emulsion) or little lumps of solid (in the case of a suspension) suspended in the liquid.

We learnt in Gr. 6 Matter and Materials that the particles of gases are far apart. This means that gases can mix very easily, because it is easy for their particles to move in amongst each other. The air we breathe is not a single gas but actually a mixture of gases! Do you know what the two most abundant components are?

Nitrogen gas and oxygen gas. Learners may say oxygen and carbon dioxide; nitrogen is actually the main component of air (roughly 80%) followed by oxygen (roughly 18%). Carbon dioxide is present in much smaller quantity.

Can you see the water vapour in the following picture of a boiling kettle? Point to it with your finger. Discuss this with your teacher and classmates and when you have agreed on an answer, draw an arrow onto the picture to indicate the water vapour.

A suggestions is to do a demonstration of this in class if you can get a kettle and plug it in to show learners the colourless steam at the spout of the kettle. Learners may point to the cloud in front of the kettle. This is not actually water vapour, which would be invisible to the human eye. The cloud forms when the water vapour cools down sufficiently to condense into micro-droplets that are visible to the human eye.

We will only see the water when it starts to condense. When the water particles condense, they become liquid water again. That means the particles start clinging together in tiny micro-droplets, which grow into larger droplets when they come together. The small cloud of in front of the kettle is actually a cloud of micro-droplets of liquid water suspended in air. This is an example of a liquid suspended in a gas.

Many things around us occur naturally as mixtures: salty sea water, moist air, soil, compost, rocks (mixture of minerals) to name a few. Many mixtures are man made, for instance; Coca Cola, paint, salad dressing and so forth.

You can ask your learners what we use paint for. Paint is used to cover walls and other surfaces. Sometimes we want to protect these surfaces against water or wind (for instance when we are painting an outside wall or roof) and sometimes we just want to make them look attractive (for instance when we paint an inside wall, or when we create a beautiful artwork). The water or oil in the paint helps us to spread the pigments more evenly over the surface that we want to cover and binds the pigments tightly so that the paint forms a protective layer.

Mixtures are very useful. However, sometimes we need to separate mixtures into their components. Remember that the substances in a mixture have not combined chemically. They have not turned into new substances, but are still the same substances as before - they have just been physically combined. That is why we can use physical methods to separate them again.

As an introduction to this you can ask learners about why they think we would want to separate mixtures. For example, imagine that our drinking water comes from a well in the ground and it is muddy. Muddy water is not good to drink. We would want separate the water from the solid material (sand or clay) before using it! Once separated, we would keep the water to drink and throw the sand away. Ask learners if they can think of a way to separate the water from the sand? Learners may suggest filtration (filtering) as a method for separating the sand and water.

Suppose you were given a basket of apples and oranges. How would you sort them? You would probably pick out all the oranges from the apples by hand. The same method may not be suitable for all mixtures. You would probably not consider sorting sugar and sand grains by hand. Why not?

The video about the Skittles sorting machine is merely for entertainment, but it could be used to introduce discussions on fun 'explorations' and hobbies that challenge us as a starting block for innovation and useful applications of technology.

When we have large quantities of materials to sort and the different particles have different sizes, we can sieve the mixture. The smaller particles will fall through the openings in the sieve, while the larger particles stay behind.

Learners did an exercise in Chapter 6 of Matter and Materials in Gr. 6 on cleaning muddy water. The chapter entitled 'Processes to purify water' required learners to design, make and evaluate their own filter. You can demonstrate the process again to refresh their memories. To set up a filter (as shown below), place a folded piece of filter paper in a funnel and place the funnel into a flask. Then, pour a mixture of muddy water into the filter and let the learners observe that clean water passes through the filter, whilst the mud/sand/clay remains behind.

Sometimes the particles that we want to remove from a mixture are so small that they will pass easily through a sieve (think of the example of the muddy water from before). Can you think of a way to overcome this?

Can you remember the activity from Gr. 6 when Tom used magnetism to separate different kinds of metals at his uncle's junk yard? The magnetic properties of the metals allowed them to be separated in this way.

You could demonstrate how, or let the learners try, to separate a mixture of sand and iron filings by using a magnet. It might help to place the magnet in a small plastic bag so the iron filings are attracted to the magnet, but do not stick to it.

The following diagram shows how magnetic separation can be used to separate a mixture of components. In the example, mineral ore that contains two compounds (one magnetic, and the other non-magnetic) is being separated. The ore grains are fed onto a revolving belt. The roller on the end of the belt is magnetic. This means that all the magnetic grains in the ore will stick to the belt when it goes around the roller, while the non-magnetic grains will fall off the end. As soon as the magnetic grains move past the magnetic roller, they will also fall down.

In the above diagram, what colour are the non-magnetic grains and into which container do they fall? Label this on the diagram. What colour are the magnetic grains and which container do they fall into?

The non-magnetic grains are yellow-orange and fall into the container on the left. the magnetic grains are grey-brown and fall into the container on the right. The diagram should be labelled as follows:

The substances in a solution are mixed on the level of individual particles. In a sugar and water solution, the sugar particles and the water particles are mixed so well that we could not distinguish them with the naked eye. You might think that mixtures that are so 'well-mixed' are impossible to separate! But as we shall soon see, this is not true.

Demonstrate this in a lesson by dissolving some salt in water in front of the class at the beginning of the lesson. Make sure they take note of the clear solution. Then pour a little into a shallow aluminium pan, like those used for baking. Place this out in a sunny spot for the duration of the lesson and allow the water to evaporate. The rate of evaporation will depend on how hot and humid it is on the day you do this. At the end of the lesson, collect the pan and show the dried salt that is left behind, just as in a salt pan. You might have to leave it out until the end of the day, depending in how hot it is.

Do you know where most of the salt that we use in South Africa comes from? South Africa gets it salt from inland salt pans, coastal salt pans and seawater. A salt pan is a shallow dam in the ground where salt water evaporates to leave a layer of dry salt.

When sea water is allowed to stand in shallow pans, the water gets heated by sunlight and slowly turns into water vapour, through evaporation. Once the water has evaporated completely, the solid salt is left behind.

If you have time to do this in class, you can demonstrate this practically. Get learners to taste the salt water before boiling and then getting them to taste the condensed water afterwards. This way they will realise that only the water has evaporated and the salt has remained behind in the kettle. You could put the ice in a small plastic bag to ensure that the ice does not slip off the plate, but the plate is still cold enough for water vapour to condense. Keeping the ice in a plastic bag will also ensure that the melting ice does not drip into the beaker collecting condensed water. You can also use a beaker or glass of salt solution over a bunsen burner and use a cold piece of glass or mirror to condense the water and collect it in another beaker.

In the picture, the salt-water solution is heated in a kettle, and a metal plate (with some ice inside to keep its outer surface cold) is held in the water vapour that is escaping from the spout of the kettle. The water vapour cools when it touches the cold metal plate and condenses. It then runs off the plate and into the collection beaker. The salt is left behind in the kettle once all the water has evaporated. But, you still have the water in the beaker.

What change of state is occurring on the cold surface of the metal plate? What is the process called? (Hint: the change of state from gas to liquid was covered in the previous chapter, under Physical properties of materials.)

The water that is lost through evaporation can be condensed on a cold surface. The cold metal plate will do the job, but it would be difficult to recover all the condensed water, because it will be dripping off the surface of the plate in many different places. Scientists have a solution for that problem: they use a special technique to separate mixtures like these without losing any of the components. The technique is called distillation.

If you have the equipment to set up this distillation process, then you can demonstrate it in class. Otherwise there are alternative materials and equipment that you can use. For example, if you do not have a Liebig condenser, you can use a piece of copper pipe. Here are two links which explain how to build your own distillation equipment: http://www.instructables.com/id/Build-a-Lab-Quality-Distillation-Apparatus/ and http://nukegingrich.files.wordpress.com/2009/06/diy-still.pdf. Another suggestion is to get learners to also do the research to see how to make their own distillation apparatus, specifically looking at materials which are easy and cheaper to come by. You do not have to have laboratory equipment to demonstrate many science experiments - many can just be done by thinking of the materials which you use in everyday life and making a plan! This also makes science more accessible to everyone.

Suppose we want to separate the water and salt in seawater. We would place the seawater in the round flask on the left of the picture (in the distillation flask). We would then boil the seawater to produce water vapour, or steam. The salt would not evaporate with the water, because only the water evaporates. The water vapour rises through the top of the flask and passes into the Liebig condenser.

The Liebig condenser consists of a glass tube within a larger glass tube. The condenser is designed in such a way that cold water can flow through the space between the tubes. This cools the surface of the inner tube. The water vapour condenses against this cold surface and flows into the receiving flask. Since the salt has not evaporated, it stays behind in the distillation flask.

The solar still video is short but provides an interesting topic for discussions: applications of separating methods; inventions; advantages and disadvantages; you could even discuss open-source projects and sharing information. The Italian inventor of the Eliodomestico solar still designed it with developing countries in mind. It is relatively cheap, easy to assemble, and requires no electricity. It is described as an eco-distiller that runs on solar power. All you need to do is pour in 5 litres of salty or impure water, tighten the cap, and leave it out in the sun. By the end of a day it can provide bacteria-free, salt-free water that is suitable for drinking. It is also an open-source project which means that anybody can use the design and replicate, modify or upgrade it, but not sell it for profit.

Ethanol boils at a temperature lower than the boiling point of water, namely 78C. Suppose you mix some water and some ethanol. The mixture is at room temperature to begin with. Now suppose you start heating the mixture. What temperature would be reached first: 78C or 100C?

We can use the same distillation method that we used for separating seawater, to separate the two liquids. The principle is exactly the same, except that we will distill the mixture more than once. Here is how it works:

The mixture of the two liquids is placed in the distillation flask and heated to the lowest boiling point. In the case of an ethanol/water mixture, that temperature would be the boiling point of ethanol, namely 78C. All of the liquid with that boiling point will evaporate, condense in the Liebig condenser, and pass into the receiving flask. The liquid with the higher boiling point will remain in the distillation flask. Suppose it contains a third substance that we want to separate. How would you do this?

We replace the receiving flask with a clean one and heat the distillation flask again, but this time to the boiling point of the second liquid. The second liquid will evaporate, condense in the cooler and flow into the clean receiving flask, leaving the final component in the mixture in the distillation flask.

Crude oil is separated into different components using distillation. The components are evaporated, starting with lighter fuel (which has the lowest boiling point), then jet fuel, then petroleum, then motor car oil, until only tar is left. We call the separated components fractions, and the process, fractional distillation.

The video about distillation of crude oil may be a bit too advanced, but it summarises the process of fractional distillation quite well and mentions relevant, real-world examples of products that are produced. Take note that the video repeatedly mentions 'hydrocarbons'. You can put the learners at ease and tell them it is not important for them to know what this means yet. The periodic table is only dealt with in Chapter 4, but you could help the learners 'decipher' that the crude oil contains a lot of hydrogen particles and carbon particles put together in different combinations (ratios). Each of the fractions that are eventually collected contain one kind of hydrocarbon combination.

Most inks are a mixture of different pigments, blended to give them just the right colour. A pigment is a chemical that gives colour to materials. When a mixture contains colourful compounds, it is often possible to separate the different components using a separating method called chromatography. Let's have a look at this next.

This is a fun activity that can be done quickly. If the class is divided into small groups and each group gets a different black marker to experiment with, the chromatograms can be stuck up on the wall afterwards for everyone to see and compare. By looking for matching chromatograms, learners can say which group had the same brand of marker, or which markers are filled with the same ink. If the ink from a certain marker will not separate in one liquid, try using another liquid in the beaker.

You could even build a story around the investigation: Stage a murder mystery in which the murderer can be identified by his (or her) black pen. Use three or four black or blue pens of different brands, and produce the unique chromatograms associated with each brand. The inks may look the same when used for writing, but they will behave differently when they are analysed by chromatography.

Laboratory Whatman filter paper no. 1 is ideal for chromatography. Alternatively, you can use coffee filters, watercolour paper or strips of paper towel. Even ordinary copy paper works, but more slowly and often this makes the colours separate better. For softer papers you may need longer strips of paper and taller containers, since the liquid is carried up the paper much faster.

Safe laboratory practice is extremely important. Take a moment to discuss risks, precautions and safety with learners. Discuss the fact that scientists often need to handle dangerous substances and/or equipment to be able to make observations.

When working with ammonia, take care to work in a fume hood or in a well-ventilated space. Leave the door and windows open, so that the fumes do not linger. Similarly, substances containing alcohol should be used in a well-ventilated space, but these are also flammable, so avoid using them in the presence of open flames.

It is always advisable to wear latex/nitrile gloves (available from pharmacies) to prevent the absorption of hazardous substances through your skin. Wear safety goggles to protect your eyes from harmful chemicals. Always have clean water nearby to rinse your eyes or wash your hands if chemicals do splash or spill.

The pigments in the ink are carried along by the liquid, but because they are different compounds, they get carried upward at different speeds. This causes them to appear as bands of different colours on the chromatogram.

Pigments migrate at different speeds because of differences in their properties: large pigment particles tend to move more slowly. Furthermore, particles that dissolve well in the liquid will tend to stay in the liquid and be carried to the top quickly, while particles that bind well to the paper will tend to move more slowly.

Some schools also use combo plates for the various practical tasks in Matter and Materials. This is encouraged and the activities in these workbooks can be adjusted slightly to work with whichever equipment and apparatus you have available to you in your school.

Also, if learners find the flow chart too complex at this stage, you can alternatively get them to write out the steps they would follow to separate all the materials in the mixture and why they have chosen each method of separation.

Imagine you are a member of a team of scientists working together in a laboratory. Your team has been given an important job. You have been given a beaker that contains a mixture of substances to separate.

This may be a difficult task for the learners to accomplish, but it is very important for the learners to be able to visualise the mixture before they start to plan the experiment. If they do not, the ideas will remain abstract and the learners may have difficulty sequencing the different separation steps correctly. You could guide them by asking the following questions. Alternately, you could prepare the mixture for them to look at it before drawing it:

So far, we have been discussing materials, their properties, how to mix them and how to separate them if they are mixed. The final section of this chapter deals with waste materials and what we can do to reduce their impact on the environment.

Over time, some of our things get old and break and we need to throw them away. When we buy food or other items, the packaging used for wrapping these items is also thrown away. But what does 'away' mean? Does it mean these waste items just disappear? Where do you think our rubbish goes once we 'throw it away'?

Allow learners to discuss this for a while. Some may know that rubbish eventually ends up on a rubbish dump somewhere, and this is a good starting point for the next activity that will require learners to think about the implications of dumping.

'There is no away' and 'There is no Planet B' refers to the same issue, namely that everything that we throw away remains part of our environment. We should be thinking of ways to reintegrate our waste by making it part of the environment in ways that will not harm the environment; reusing, recycling and repurposing waste items and materials in creative and innovative ways. 'There is no Planet B' is also a play on words that refers to the well-known notion of a 'Plan B' that can be reverted to if the original plan (plan A) fails.

Many things can be reused or recycled. Many of the waste that is not recyclable can be turned into compost for the garden. Learners may have interesting opinions about this question, and hopefully it will get them thinking about creative ways of reusing and repurposing waste.

For this activity, learners must use materials that would ordinarily go into the rubbish bin in your home (cereal boxes, cardboard, plastic wrappers etc) to make a poster that will create awareness for the environmental problem that concerns them the most. The poster should also contain suggestions for solving the problem. Here are a few ideas, but they only need to choose one:

In some suburbs, recycling is actively encouraged and special transparent recycling bags are provided for this purpose. Do you have recycling in your community? Is the recyclable waste collected from your home or do you have to drop it off at a container or a depot? Did you know that some people even make money selling recyclable waste that they collect?

In this short activity, we are going to think about creative ways of dealing with household waste items that are not in the 4 categories discussed above. For each item in the table, some recycling ideas have been given.

Invite a chemist/scientist: Do you know someone who is a chemist or a chemical engineer? Perhaps you live near a university? If you do, you could invite a chemist to come to your school and talk to your class about the work that chemists do. Alternatively, you could visit the chemist at their workplace and ask them to show you around. You can get learners to prepare a few questions beforehand; for instance, you could ask them about their work, their training and what they think are the qualities needed if one wanted to become a chemist. Just remember to make an appointment first!

Chemists study various chemical elements and compounds, their properties and how they react with each other. We will learn about elements and compounds in the next chapter. Chemists are also responsible for developing new materials with specific properties; such as new medicines; innovative materials for building buildings and other structures; materials that could be used for making fuels from renewable sources and many others.

If you study chemistry after you have finished school, you can work as a researcher, a laboratory technician, a science teacher and many other important and stimulating jobs! Be curious and discover the possibilities! Science can help us solve problems in the world around us.

This is not for assessment purposes and is aimed at getting learners to start thinking about the possibilities for their futures. The emphasis should be on discovering the possibilities that science, technology maths and engineering give us, not just work opportunities, but using them to solve problems in the world.

A useful site to find out more about some chemistry-related careers. http://portal.acs.org/portal/acs/corg/content?_nfpb=true&_pageLabel=PP_SUPERARTICLE&node_id=1188&use_sec=false&sec_url_var=region1&__uuid=964e0712-eaa0-4f2a-a03d-689d0a3cd62c

We looked at physical methods to separate mixtures and these are shown in the concept map. Give an example of the types of mixtures you could separate using three of these methods. What negative consequences does human waste have on the environment? Fill these in the concept map.

Two important words have been left out of the following paragraph. The missing words are chemical and physical. Rewrite the sentences and fill in the missing words in the paragraph by placing each one in the correct position:

The components in a mixture have not undergone any _____ changes. They still have the same properties they had before they were mixed. That is why mixtures can be separated using _____ methods. [1 mark]

A vacuum cleaner creates a suspension of dust in air as it sucks up the dust on the floor. Clean air comes out of the vacuum cleaner. How does the vacuum cleaner separate the dust from the air? [2 marks]

The vacuum cleaner has a fine filter in it which traps the dust particles. The clean air is able to get through the filter, but the dust is left behind. Some more modern vacuum cleaners also filter the air through water which cleans the air even further. Some very fine dust particles may be able to get through the fine filter, but if the air is passed through water, then even very fine particles are trapped.

All Siyavula textbook content made available on this site is released under the terms of a Creative Commons Attribution License. Embedded videos, simulations and presentations from external sources are not necessarily covered by this license.

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