CHEMISTRY FORM 1
- 1.1 What is matter?
- 1.2 What is Chemistry?
- 1.3 What does matter consist of?
- 1.4 Are the particles in matter stationary?
- 1.5 Arrangement, distance, and attraction between particles
- 1.6 Properties of matter (volume, shape and compression)
- 1.7 Conductors and non-conductors
- 1.8 Sources of heat
- 1.9 Bunsen burner
- 1.10 Role of Chemistry in society
- 2.1 Pure substances
- 2.2 Mixtures
- 2.3 Separation of Mixtures
- 2.4 Separation of solid-solid mixture
- 2.5 Separation of insoluble solid-liquid mixture
- 2.6 Separation of soluble solid-liquid mixture (solution)
- 2.7 Separation of immiscible liquid-liquid mixture
- 2.8 Separation of miscible liquid-liquid mixtures (solution)
- 2.9 Separation of liquid-gas mixture
- 2.10 Selecting and using appropriate methods of separating mixtures
- 2.11 Kinetic theory of matter
- 2.12 Classification by physical states
- 2.13 Effect of heat on physical states
- 2.14 Effect of impurities on melting and boiling points
- 2.15 Permanent and non-permanent changes
- 2.16 Definitions, chemical symbols and equations
- 3.1 Simple acid-base indicators
- 3.2 Universal indicators and pH scale
- 3.3 Reactions of acids with metals
- 3.4 Reactions of acids with carbonates and hydrogen-carbonates
- 3.5 Reactions of acids with bases
- 3.6 Effects of acids on substances
- 3.7 Applications of acids and bases
- 4.1 Composition of Air
- 4.2 Fractional distillation of liquid air
- 4.3 Rusting
- 4.4 Oxygen
- 4.5 Burning of substances in air
- 4.6 Atmospheric pollution
- 5.1 Candle wax and water
- 5.2 Reactions of metals with liquid water
- 5.3 Reaction of metals with steam
- 5.4 Preparation of hydrogen gas
Simple Classification of Substances and Separation of Mixtures: Separation of miscible liquid-liquid mixture (solution)
2.0 Simple Classification of Substances and Separation of Mixtures
2.8 Separation of miscible liquid-liquid mixtures (solution)
Some liquids such as water and ethanol, water and methanol, or kerosene and petrol mix uniformly (form solutions). The methods described earlier cannot separate them.
How can we separate ethanol and water?
Materials and substances required
- Distillation flask and fractionating column
- Liebig condenser
- Tripod stand, wire gauze, retort stands, beakers, thermometer, solution of ethanol in water, wooden splint
Open the link fractional distillation to observe how ethanol is separated from its uniform mixture (solution) with water.
- What is the property of the mixture that makes fractional distillation possible?
- What are the boiling points of water and ethanol? Water -- Ethanol --
- How can we know when all the more volatile component has distilled off so that we stop heating or replace the beaker receiving the distillate?
- What is the use of a thermometer in the distillation process?
- What is the use of porcelain chips at the bottom of the distillation flask?
- What is the use of fractionating column?
- What is the function of glass beads in the fractionating column?
- Why is the process called fractional distillation?
- Explain the use of a Liebig condenser.
- How can we test whether the distillate collected is ethanol and not water?
- Why is the cold water inlet of a Liebig condenser at the lower end?
Answers to Questions 2.8
Separation of miscible liquid-liquid mixtures makes use of difference in boiling points. During heating, the component with a lower boiling point (more volatile) reaches its boiling point first, boils off, and condenses into a separate container as a distillate (condensate).
The component with the higher boiling point (less volatile) remains in the flask.
Fractional distillation is used to separate ethanol (an alcohol) from its brewing mixture with water. The process is also used in oil refinery to separate crude oil into various components such as petrol, diesel, kerosene, cooking gas, and butimen (tar).