Question 2
D is a simple salt. The following tests were carried out on D. Copy and complete the table
(C) Based on the observations and deductions, state the:
(i) chemical formula of D;
(ii) name of D.
[13 marks]
Observation
The question tested qualitative analysis. Majority of the candidates responded to it.
In part (a), majority of the candidates could not write the correct inferences from the observations.
In part (b), majority of the candidates could not identify SO2 gas and SO32- from the odour and reaction with acidified KMnO4. However, majority of the candidates got the confirmatory test for Cu2+, but lost marks to wrong observations.
In part (c), majority of the candidates could not write the chemical formula of D.
The expected answers include:
(c) (i) Chemical formula of D is CuSO3
(ii) Name of D – Copper (II) trioxosulphate (IV)