QUESTION 21 (3 marks)
Reactants A and B are placed in a 1.00 L container and react to form product C. The reaction then reaches equilibrium.
a) Explain why a reversible arrow (
) is used to symbolise this reaction.
[1 mark]
b) Deduce whether the equilibrium for the reaction lies towards the reactants or products. Explain your reasoning.
[2 marks]
QCAA guide · typeset solution
QCAA sample response and mark allocation
21a) | The reversible arrow indicates that the reaction occurs in both directions (forward and reverse) simultaneously. | • explains that forward and reverse reactions occur simultaneously [1 mark] |
21b) | Kc is greater than 1, therefore the equilibrium for the reaction lies towards the products. | • deduces the equilibrium lies towards the products [1 mark] • explains that Kc is greater than 1 [1 mark] |
QCAA sample response and marking criteria reproduced from the official guide.
Compare your working with the guide above.