Programme Outline
This programme uses laboratory demonstrations and graphics to illustrate and explain the materials focused on. Some of the demonstrations could be duplicated in a school laboratory and used in conjunction with the programme, which employs graphics to highlight what is being illustrated.
The programme is divided into three sequences:
- 1.Crude Oil
- 2.Air (Oxygen and Nitrogen)
- 3.Reducing Metal Oxides
Crude Oil
00.00 The composition of crude oil
Crude oil contains a mixture of hydrocarbon compounds with carbon chains of different lengths.
00.59 Simple laboratory distillation of crude oil
Heating crude oil gently vaporises the hydrocarbons with the lowest boiling points. The vapour is cooled and condensed to give a fraction with a low boiling point. Fractions with higher boiling points are obtained by increasing the temperature.
03.12 Improving the fractionating process
Adding a fractionating column and Liebig condenser allows the crude oil to be fractionally distilled. Separation of crude oil into fractions takes place in the fractionating column.
04.06 Industrial distillation of crude oil
The oil industry uses fractional distillation. In an industrial fractionating tower, fractions of crude oil with small molecules collect at the top while the fractions with the largest molecules run off near the bottom.
Air (Oxygen and Nitrogen)
05.00 Burning substances in oxygen
Oxygen relights a glowing splint. Non-metals burn in oxygen to produce acidic oxides. Reactive metals produce alkalis when they burn in oxygen. About one-fifth of the atmosphere is oxygen.
08.23 Properties of nitrogen
A demonstration of the unreactive nature of nitrogen gas and the use of liquid nitrogen as a coolant.
09.14 Distilling liquefied air
Liquid nitrogen is used to liquefy air. As the liquid air warms up, nitrogen boils off first, followed by oxygen which has a slightly higher boiling point.
Reducing Metal Oxides
10.27 Finding metals in the Earth's crust
The occurrence of metals in their native state and as ores.
11.06 Reducing copper oxide
Hot copper oxide is reduced in hydrogen gas. Safety precautions are stressed. The chemical changes are explained in terms of reduction and oxidation.
12.28 Another way of reducing copper oxide
Using carbon as the reducing agent is a safer way of extracting copper from its oxide. The reaction is again described in 'redox' terms.
13.12 Reducing oxides of other metals
The reaction of carbon with other metal oxides is investigated. Lead is displaced from its oxide, but with iron oxide nothing happens.
