Question

In which of the following reaction (s) $H_{2}S{O}_4$ can't act as an oxidising agent?

• A. $C_{12}{H}_{22}{O}_{11}\stackrel{H_{2}S{O}_4}{\to }12C+11H_{2}O$
• B. $S+2H_{2}S{O}_4\to 3S{O}_2+2H_{2}O$
• C. $Cu+2H_{2}S{O}_4\to CuS{O}_4+S{O}_2+2H_{2}O$
• D. All of the above

Answer 1

The correct option is A $C_{12}{H}_{22}{O}_{11}\stackrel{H_{2}S{O}_4}{\to }12C+11H_{2}O$

$\stackrel{0}{C}u+H_{2}S{O}_4\to \stackrel{+2}{C}uO+H_{2}O+S{O}_2$
here $H_{2}S{O}_4$ is oxidising Cu thus acting as oxidant.
$\stackrel{0}{S}+2H_{2}S{O}_4\to 3\stackrel{+4}{S}{O}_2+2H_{2}O$ here $H_{2}S{O}_4$ is oxidising S thus acting as oxidant.
$C_{12}{H}_{22}{O}_{11}\stackrel{H_{2}S{O}_4}{\to }12C+11H_{2}O$
But, in this reaction it is not acting as an oxidising agent. It is acting as an dehydrating agent. Hence option (a) is the correct answer.