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Matter: Anything that occupies space is called matter.
Example: Air, water, rock etc.,
Matter exists in our surroundings in both pure and impure forms. (Scroll down to continue …).
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Mixture: A mixture is a matter that contains more than one pure substance in any ratio/proportion.
A mixture is an impure form of matter.
Example:
Water in milk, lemon juice, Ginger Garlic paste, etc.,
The mixture may or may not be separated into its constituent particles by physical processes.
Substance: A matter that cannot be separated into its constituent particles by any physical process is known as a substance.
Example:
Solution: A homogeneous mixture of two or more substances is called a solution.
Example:
Tea, sugar, and common salt are dissolved in water.
Alloy: A homogeneous mixture of metals is called an alloy.
Properties of the Solution:
- A solution is a homogeneous mixture
- Particles are extremely small, not visible to the naked eye
- The light path is invisible in solution.
- Solute particles cannot be separated by filtration
Concentration of solution: The concentration of a solution is the amount of solute present in a given quantity of the solution.
Unsaturated and Saturated Solutions: a solution in which a larger quantity of solute can be dissolved without raising its temperature, is called an unsaturated solution.
• A solution in which no more solute can be dissolved at a certain temperature, is called a saturated solution.
Solubility: The maximum amount of a solute that can be dissolved in 100 grams of a solvent at a specified temperature is known as the solubility of the solute in that solvent.
Suspension: a heterogeneous mixture of solids and liquids where the solid particles are suspended throughout the medium.
Example: Mixture of chalk powder and water
Properties of Suspension
• Particles are visible to the naked eye
• Light path in a suspension is visible
• Particles settle down
Colloidal Solution: Colloidal Solution Is a heterogeneous mixture, but appears to be homogeneous.
Examples: Milk, soap lather, soda water, pumice stone, rubber, bread, fog, cloud, insecticide spray, butter, etc.
Properties of colloidal solutions
• Heterogeneous mixture
• Particle size is small, not visible to the naked eye
• Light path can be visible;
• Particles do not settle down
• Substances cannot be separated by filtration
Tyndall Effect: Scattering of light beam by suspended particles in the solution.
Physical and Chemical changes:
Physical and change: The changes in which no new substances are formed are called physical changes.
Chemical change: The changes in which new substances are formed are called chemical changes.
SEPARATION OF MIXTURES
The method of separation depends on both the type of mixture and the physical properties of its constituents.
These are :
(i) The physical state of the constituents.
(ii) The differences in the physical properties
of the constituents, such as:
(a) boiling point
(b) melting point
(c) density
(d) magnetic properties
(e) ability to sublime
(f) volatility
(g) solubility in various solvents.
• Evaporation: Used for separating mixtures of volatile solvents and non-volatile solutes.
Working Principle:
One component should be non-volatile. It may or may not be soluble in water.
Example: Separating salt from its solution
• Centrifugation used for separating components based on the difference in their weights.
Working Principle:
Difference in the densities of two liquids.
Example: Separating mixtures of cream from milk
• Separating Funnel: Used for separating two or more immiscible liquids.
Working Principle:
Immiscible liquids with different densities get separated into different layers if they are in the same container.
Example: Separating oil and water
Sublimation:
Sublimation is the process of converting a solid into vapour and returning it to the solid state without passing through the liquid state.
Sublimation is used to separate sublimable solids from their mixtures.
Working Principle:
One of the components can be sublime.
Example: Separating ammonium chloride from a mixture
Chromatography:
The process of separating the different dissolved constituents of a mixture by their adsorption (adsorption refers to the collection of one substance on the surface of another substance.) over an appropriate adsorbing material is called chromatography.
Chromatography is used to separate those solutes that dissolve in the same solvent.
Working Principle:
Adsorption/partition
Example: Separating the components of a dye
Distillation:
Distillation is the process of heating a liquid to convert it into vapours and then condensing the vapours back into a liquid.
Distillation is used to separate two miscible liquids that boil without decomposition.
Working Principle:
One component should be a soluble solid in a liquid.
Example: Separating a mixture of acetone and water
Fractional distillation
Fractional distillation is a process that involves the distillation and collection of fractions or different liquids boiling at different temperatures.
Fractional distillation is used to separate a mixture of liquids when their boiling temperatures differ by less than 25 K.
Example: Separating different components of petroleum
Crystallization: Used to separate pure solids from a solution by forming crystals.
Working Principle:
A solid dissolved in a liquid is separated by evaporating the solvent completely by heating the mixture.
Example: Obtaining pure crystals of copper sulphate from an impure sample.
Differences Between Mixture And Compound
| Property | Mixture | Compound |
| Nature | When two or more elements or compounds or both are mixed together, such that they do not combine chemically, a mixture is formed. | When two or more elements unitechemically, a compound is formed. |
| Structure | Mixtures are generally heterogeneous. However, some mixtures can be homogeneous. | Compounds are always homogeneous. |
| Composition | In case of mixtures their constituents can be present in any ratio, i.e., mixtures havevariable composition. | In case of compounds, the constituents arepresent in a fixed ratio by weight. |
| Properties | The constituents of a mixture retain theirindividual chemical and physical properties. | The properties of a compound are entirelydifferent from the properties of itsconstituents |
| Separation of constituents | The constituents of a mixture can beseparated by applying physical methods likesolubility, filtration, evaporation, distillation,use of magnet, etc. | The constituents of a compound cannot beseparated by applying physical methods.However, constituents of a compound can beseparated by chemical means. |
| Energy change | There may or may not be energy changeduring the formation of mixture. | During the formation of a compound eitherthe energy is absorbed or given out. |
| Type of Mixture | Nature of Mixture | Example | Separation Method |
| Solid – solid | Heterogeneous | Iron + Sand; | Magnetic separation |
| Solid – solid | Heterogeneous | Iodine + Sand | Sublimation |
| Solid – solid | Heterogeneous | Iron + Sulphur | Solvent extraction |
| Solid – solid | Heterogeneous | Nitre + Common salt | Fractional crystallisation |
| Solid – liquid | Heterogeneous | Sand+Water; Clay + Water | Sedimentation-decantation |
| Solid – liquid | Heterogeneous | Chalk + Water; PbCl₂ + Water | Filtration |
| Solid – liquid | Homogeneous | Common salt in seawater | Evaporation |
| Solid – liquid | Homogeneous | Iodine + Methyl alcohol | Distillation |
| Liquid – liquid | Homogeneous | Methyl alcohol + Ethyl alcohol | Fractional distillation |
| Liquid – liquid | Homogeneous | Oil + Water; Mercury + Water | Separating funnel |
| Liquid – gas | Homogeneous | Ammonia + Water | Boiling of liquid |
| Complex Mixture | Homogeneous | Colouring matter in ink | Chromatography |
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