CAIE A Level Chemistry 9701 · Equilibria
The reaction between sulfur dioxide and oxygen is reversible:
(a) Explain what is meant by a dynamic equilibrium and why a closed system is needed.
(b) The reaction is carried out in a closed container at constant temperature. The pressure of the system is increased. Use Le Chatelier's principle to explain the effect of this change on the position of equilibrium and on the value of .
5 marks, so the mark scheme is looking for about 5 separate creditworthy points. Making the same point twice in different words earns it once.
Explain means: Give the reasons or the mechanism: why or how something happens. Link each point to the next with because, so or which means. A list of facts with no links usually loses the reasoning marks.
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