In which of the following reactions conc. `H_(2)SO_(4)` is used as an oxidising reagent?

Options

A. `CaF_(2)+H_(2)SO_(4)rarrCaSO_(4)+2HF`
B. `2HI+H_(2)SO_(4)rarrI_(2)+SO_(2)+2H_(2)O`
C. `Cu+2H_(2)SO_(4)rarrCuSO_(4)rarrCuSO_(4)+SO_(2)+2H_(2)O`
D. `NaCl+H_(2)SO_(4)rarrNaHSO_(4)+HCl`

Answer

B, C

Explanation

In given four reactions, option (B) and (C) represent oxidising behaviour of `H_(2)SO_(4)` that oxidising agent reduces itself as oxidation state of central atom decreases. The reaction is given below :
`overset (-1)(2HI)+H_(2)overset(-6)(SO_4)rarroverset(0)(I_2)+overset(-4)(SO_4)+2H_(2)O`
`overset(0)(Cu)+2H_(2)overset(-6)(SO_4)rarroverset(+2)(Cu)SO_(4)+overset(+4)(SO_2)+2H_(2)O`