Question

The oxidation state of nitrogen is correctly given for :

• A. $\begin{array}{cc}Compound& Oxidationstate\\ \left[Co{\left(N{H}_3\right)}_{5}Cl\right]{Cl}_2& 0\end{array}$
• B. $\begin{array}{cc}Compound& Oxidationstate\\ N{H}_{2}OH& -2\end{array}$
• C. $\begin{array}{cc}Compound& Oxidationstate\\ {\left(N_2{H}_5\right)}_{2}S{O}_4& +2\end{array}$
• D. $\begin{array}{cc}Compound& Oxidationstate\\ {Mg}_3{N}_2& -3\end{array}$

Answer 1

The correct option is D $\begin{array}{cc}Compound& Oxidationstate\\ {Mg}_3{N}_2& -3\end{array}$

(A) oxidation number of $N$ is 0

$\left[CO{\left(N{H}_3\right)}_5\text{Cl}\right]{\text{Cl}}_2$

we know ,$Cl$ has -1 state,$N{H}_3$ is neutral

i.e O charge, $H^{+}$ has a +1 charge.

so net charge should be 0 .

Let $x$ be the charge on $N$ atom

$x\times 1+3\times 1=0$

so oxidation state of Nitrogen is -3.

hence $A$is wrong

(B) ${NH}_{2}OH$ oxidation number of $N$ is -2

we know net charge on $H^{+}$ is +1 , net charge on $OH$ is -1

since compound should have neutral charge

Let $x$ bo charge on N atom

$x\times 1+1\times 2-1\times 1=0$

$x=-1$ so oxidation state of Nitregen is -1

hence $B$ is wrong

( C) ${\left(N_2{H}_5\right)}_{2}S{O}_4$ oxidation number of $N$ is +2

$[2\times x+5\times 1]\times 2-2\times 1=0$

$\Rightarrow x=-2$

so $C$ is wrong

(D) $M{g}_3{N}_{2}O\cdot S\Rightarrow -3$

we know oxidation state of $Mg$ is +2

Let $x$ bo charge on N atom

$3\times 2+2\times x=0$

$x=-3$ so oxidation state of Nitregen is -3

hence $D$ is correct