CSEC Chemistry · January 2010 · Paper 2 · Question 1(a)(vii)

Copper(II) oxide reacts with dilute sulphuric acid to produce either anhydrous or hydrated salts. The type of salt depends on the procedure. Table 1 shows 5 experiments with different masses of anhydrous copper(II) salt formed by reacting varying masses of copper(II) oxide with 50 cm³ of 1 mol dm⁻³ sulphuric acid. A reading for Experiment 3 is missing from Table 1.

Explain why there is no change in the mass of salt produced for Experiments 4 and 5.

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