Question 3B
- (i) Describe briefly how copper (II) tetraoxosulphate (VI) solution could be converted to
- State what would be observed when hydrogen gas is passed over heated copper (II) oxide.
zinc tetraoxosulphate (VI) solution in the laboratory.
(ii) Write a chemical equation for the reaction in 3(a)(i).
[4 marks]
[1 mark]
Observation
In part (a), majority of the candidates described how copper (II) tetraoxosulphate (VI) could be converted to zinc tetraoxosulphate (VI) solution, but could not write a chemical equation for the reaction.
In part (b), majority of the candidates stated what would be observed when hydrogen gas is passed over heated copper (II) oxide.
The expected answer include:
(a) (i) Pure zinc metal / granules is added to the copper (II) tetraoxosulphate (VI)
Solution in a test tube / beaker. The mixture is shaken for a while to quicken the
reaction. The blue solution turns colourless with brown deposit
(ii) Zn(s) + CuSO4(aq) → Cu(s) + ZnSO4(aq)
(b) A brown solid is formed