Question

In balancing the reaction $xZn+N{O}_3^{-}+y{H}^{+}\to xZ{n}^{2+}+N{H}_4^{+}+z{H}_{2}O$, $x,y$ and $z$ are respectively :

• A. $4,10,3$
• B. $3,8,3$
• C. $3,10,3$
• D. $4,3,10$

Answer 1

The correct option is A $4,10,3$

GIven a reaction:

$xZn+N{O}_3^{-}+y{H}^{+}\to xZ{n}^{2+}+N{H}_4^{+}+z{H}_{2}O$

First, atoms other than $H$ and $O$ needs to be balanced.

In this reaction , $Zn$ is oxidized to $Z{n}^{2+}$ ion. The net increase in the oxidation number is $+2$.
Nitrogen is reduced. Its oxidation number changes from $+5$ to $-3$. The net decrease in oxidation number is $-8$.

Thus, factor $4$ is added to zinc atom and zinc ion.

To balance oxygen atoms, one water molecule is added.
To balance hydrogen atoms, coefficient $10$ is added to $H^{+}$ ions on the left.

Hence, the coefficients $x,y$ and $z$ are $4,10$ and $3$ respectively.