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(a) Catalytic converters in the exhaust systems of cars contain catalysts - Edexcel - GCSE Chemistry - Question 3 - 2015 - Paper 1
Question 3
(a) Catalytic converters in the exhaust systems of cars contain catalysts. (i) Explain what is meant by the term catalyst. (ii) This reaction takes place in a cata... show full transcript
Worked Solution & Example Answer:(a) Catalytic converters in the exhaust systems of cars contain catalysts - Edexcel - GCSE Chemistry - Question 3 - 2015 - Paper 1
Step 1
Explain what is meant by the term catalyst.
Answer
A catalyst is a substance that speeds up or increases the rate of a chemical reaction. It does this by providing an alternative reaction pathway with a lower activation energy. Importantly, a catalyst is chemically unchanged at the end of the reaction, meaning that it can be used repeatedly without being consumed.
Step 2
On the axes below, draw labelled lines to show the relative energies of the reactants and products in this reaction.
Answer
In an exothermic reaction, the energy level of the products is lower than that of the reactants. Therefore, you should draw a horizontal line to represent the reactants (carbon monoxide and oxygen), which starts higher on the vertical axis of energy. Then, draw a line that decreases downwards to a lower horizontal line, which represents the products (carbon dioxide). This indicates that energy is released in the reaction. Make sure to label the lines appropriately.