pBlock ElementsII - Result Question 119
####4. The correct order of the oxidation states of nitrogen in NO, $NO _2, NO _2$ and $N _2 O _3$ is
(2019 Main, 9 April I)
(a) $NO _2<NO<N _2 O _3<N _2 O$
(b) $N _2 O<NO<N _2 O _3<NO _2$
(c) $O _2<N _2 O _3<NO<N _2 O$
(d) $N _2 O<N _2 O _3<NO<NO _2$
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Solution:
- The correct increasing order of oxidation state of nitrogen for nitrogen oxides is
$$ \stackrel{+1}{N} _2 O<\stackrel{+2}{N} O<\stackrel{+3}{N} O _2<\stackrel{+4}{N} O _2 $$
- Oxidation state of $N$ in $N _2 O$ is
$$ \begin{aligned} & 2(x)-2=0 \ & x=+\frac{2}{2}=+1 \end{aligned} $$
- Oxidation state of $N$ in $NO$ is
$$ \begin{aligned} x-2 & =0 \ x & =+2 \end{aligned} $$
- Oxidation state of $N$ in $N _2 O _3$ is
$$ \begin{array}{r} 2 x+3(-2)=0 \ x=\frac{6}{2}=3 \end{array} $$
- Oxidation state of $N$ in $NO _2$ is
$$ \begin{aligned} x+2(-2) & =0 \ x-4 & =0 \ x & =+4 \end{aligned} $$
