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 a 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
Air and Combustion: Fractional distillation of liquid air
4.0 Air and Combustion
4.2 Fractional distillation of liquid air
Fractional distillation is also used to separate components of air (nitrogen, oxygen, and rare gases). This is possible because the components have different boiling points.
Air is first condensed (liquefied). It then flows into a fractionating column where it is allowed to boil. The component with the lowest boiling point boils off first and its vapour is condensed and stored in a separate tank. The component with the next lowest boiling point is collected next and so on.
NB: During liquefaction, carbon (IV) oxide sublimes (deposits) at -78 °C and is removed as a solid.
- Which component of air will be:
- the first to liquefy during cooling
- the last to liquefy during cooling
- the first to boil during distillation?
- Search the Internet for
- two uses of helium
- one use of argon
- one use of neon
- one use of carbon (IV) oxide.
Answers to Questions 4.2
It is through fractional distillation that the oxygen used in hospitals on patients with breathing difficulty is prepared.