Question

Whwn lead nitrate is strongly heated, the oxidation number of which of the following atoms change?

• A. Only in $Pb$ and $N$
• B. Only in $N$ and $O$
• C. $Pb$, $N$ and $O$
• D. Only in $N$

Answer 1

The correct option is B Only in $N$ and $O$

When lead nitrate is strongly heated, lead oxide, nitrogen dioxide and oxygen are obtained. In this reaction, the oxidation number of lead remains same but the oxidation numbers of nitrogen and oxygen change.
The oxidation number of nitrogen changes from $+5$ to $+4$.
The oxidation number of oxygen changes from $-2$ to $0$.
The oxidation number of lead remains $+2$.
The reaction is given below:
$2Pb(N{O}_3{)}_2\stackrel{\Delta }{\to }2PbO+4N{O}_2+O_2$