2:13 know that carbon dioxide is a greenhouse gas and that increasing amounts in the atmosphere may contribute to climate change
Carbon dioxide (CO2) is a greenhouse gas.
It absorbs infra-red radiation and therefore warms the atmosphere. This leads to global warming.
This may cause climate change.
Crude Oil is a mixture of hydrocarbons.
4:08 describe how the industrial process of fractional distillation separates crude oil into fractions
- Crude oil is separated by fractional distillation.
- Crude oil is heated and the oil evaporates.
- It then goes into the tower. As the vapours rise up the tower the temperature falls.
- Different sized fractions condense at different heights because they have different boiling points.
- Smaller molecules condense high up the tower. Larger molecules condense low down in the tower.
- The fractions are collected.
4:09 know the names and uses of the main fractions obtained from crude oil: refinery gases, gasoline, kerosene, diesel, fuel oil and bitumen
Crude oil is separated into fractions by the process of fractional distillation.
The boiling point increases as the number of carbon atoms (chain length) increases.
The viscosity increases as the number of carbon atoms (chain length) increases.
The viscosity of a fluid describes how easily it flows. Water has a low viscosity, it flows very easily. Crude oil has a higher viscosity than water, it does not flow very easily.
4:12 know the possible products of complete and incomplete combustion of hydrocarbons with oxygen in the air
Complete Combustion happens when there is enough oxygen available, producing carbon dioxide (CO2) and water (H2O)
Incomplete Combustion happens when there is not enough oxygen available, with possible products being carbon monoxide (CO), carbon (C, soot), carbon dioxide (CO2) and water (H2O)
4:13 understand why carbon monoxide is poisonous, in terms of its effect on the capacity of blood to transport oxygen references to haemoglobin are not required
Carbon monoxide may be produced from the incomplete combustion of fuels:
Carbon monoxide is poisonous because it reduces the capacity of the blood to carry oxygen.
4:14 know that, in car engines, the temperature reached is high enough to allow nitrogen and oxygen from air to react, forming oxides of nitrogen
When fuels are burned in vehicle engines, high temperatures are reached.
At these high temperatures nitrogen and oxygen from the air react to produce nitrogen oxides:
Alkanes have the general formula CnH2n+2
This means that to work out the number of hydrogens, you double the number of carbons and then add two.
4:21 understand how to draw the structural and displayed formulae for alkanes with up to five carbon atoms in the molecule, and to name the unbranched-chain isomers
The displayed formulae show all the atoms and bonds drawn out.
The molecular formulae just show the number of each type of atom in the molecule.