1.2 Reaction Rates Learning Outcomes
In all cases pupils should be able to state that:
Following the course of a reaction
1
Reactions can be followed by measuring changes in
concentration, mass and volume of reactants and products
2
The average rate of a reaction, or stage in a reaction, can
be calculated from the initial and final quantities and the
time interval
3
The rate of a reaction, or stage in a reaction, is
proportional to the reciprocal of the time taken, ie if the
rate is high the time taken will be small, and vice versa
Factors affecting rate
4
The rates of reactions are affected by changes in
concentration, particle size and temperature
5
The collision theory can be used to explain the effects of
concentration and surface area on reaction rates.
Catalysts
6
Catalysts are substances which speed up some reactions
and are not used up by the reaction
7
Catalysts can be classified as either homogeneous or
heterogeneous
8
There are many everyday examples of uses of catalysts
9
Catalysts are used in many industrial processes
10
Heterogeneous catalysis works by the adsorption of
reactant molecules
11
The surface activity of a catalyst can be reduced by
poisoning
12
Impurities in the reactants result in industrial catalysts
having to be regenerated or renewed.
13
Catalytic convertors are fitted to cars to catalyse the
conversion of poisonous carbon monoxide and oxides of
nitrogen to carbon dioxide and nitrogen
14
Enzymes catalyse the chemical reactions which take place
in the living cells of plants and animals
15
There are many everyday examples of uses of enzymes
16
Enzymes are used in many industrial processes.