Question

Identify oxidant and reductant in the following reaction:
$Cu+4HN{O}_3\left(dil\right)\to Cu(N{O}_3{)}_2+2H_{2}O+2NO$

• A. $HN{O}_3,Cu$
• B. $Cu,H_{2}O$
• C. $Cu,HN{O}_3$
• D. None of these

Answer 1

The correct option is A $HN{O}_3,Cu$

In the following redox reaction:
$Cu+4HN{O}_3\left(dil\right)\to Cu(N{O}_3{)}_2+2H_{2}O+2NO$
Oxidation states,
$0\text{for}Cu+5\text{for}N+4\text{for}Cu+2\text{for}N$

Oxidation state of $Cu$ is increasing so it is being oxidised by $HN{O}_3$. So, $HN{O}_3$ is oxidant.

Oxidation state of $N$ is decreasing so it is being reduced by $Cu$. So, $Cu$ is reductant.