CSEC Chemistry · May/June 2011 · Paper 2 · Question 1(a)(xi)

Students investigated the electrolysis of copper(II) sulphate using copper electrodes. They measured the mass of the copper cathode at five-minute intervals after passing a 0.2 A current. Table 1 shows the initial mass and masses for some readings.

Suggest a reason for the difference between the mass of copper obtained in (x) above and that recorded in Table 1.

This question uses a figure or table from the paper — you'll see it when you practise.