This question concerns the reaction of copper(ii) carbonate with dilute hydrochloric acid. The equation for the reaction is:

CuCO₃(s) + 2HCl(aq) → CuCl₂(aq) + CO₂(aq) + H₂O(l)

a. Sketch a graph to show the rate of production of carbon dioxide when an excess of dilute hydrochloric acid is added. The reaction lasts 40 s and produces 60 cm³ of gas.

b. Find on your graph the part which shows:

(i) Where the reaction is at its fastest

(ii) When the reaction has stopped.

c. Calculate the mass of copper(ii) carbonate used to produce 60 cm³ of carbon dioxide. (Ar: C = 12; O = 16; Cu = 63.5. One mole of a gas occupies 24 dm³ at room temperature and pressure (rtp).)

d. Sketch a further graph using the same axes to show what happens to the rate at which the gas is produced if:

(i) The concentration of the acid is decreased

(ii) The temperature is increased.