Explanation:
Copper sulphate reacts with potassium iodide to form cuprous iodide and iodine.
2CuSO
4
+4KI→Cu
2
I
2
↓+I
2
+2K
2
SO
4
Thus, CuI
2
is not formed in this reaction.
Hence, the option B is incorrect and option A is correct.
The liberated iodine is titrated with sodium thiosulphate to form sodium tetrathionate.
2Na
2
S
2
O
3
+I
2
→Na
2
S
4
O
6
+2NaI
Iodine is reduced and sodium thiosulphate is oxidized.
