Question

In a reaction, $4$ mol of electrons are transferred to $1$ mol of $HN{O}_3$. The possible product obtained due to reduction is :

• A. $0.5$ mol of $N_2$
• B. $0.5$ mol of $N_{2}O$
• C. $1$ mol of $N{O}_2$
• D. $1$ mol of $N{H}_3$

Answer 1

Answer: (B)

$0.5$ mol of $N_{2}O$

When 1 mol $HN{O}_3$ gains 4 electrons , then:
As the oxidation state of N in $HN{O}_3$ is +5 , then after gaining it must be +1.
So change in oxidation state in by for unit, so compound must be $N_{2}O$, among all given.
So reaction (balanced ) is as follows:
$2HN{O}_3+4e-\to N_{2}O$
so as 2 moles converts to 1 mol $N_{2}O$
the 1 mol must produce 0.5 mol of $N_{2}O$. So option B is the answer.