Question

The oxidation number of chlorine in $HCl{O}_4$ is

• A. + 7
• B. + 5
• C. + 3
• D. - 1

Answer 1

Answer: (A)

$HCl{O}_4$
(O.N. of $H$ ) $+$ (O.N. of $Cl$ ) $+($ O.N. of $O)=0$
Let oxidation number of $Cl=x$
We know that
Oxidation number of $H=+1$
Oxidation number of $O=-2$
Therefore, $+1+x+4(-2)=0$
$1+x-8=0$
$x=+7$
So, the oxidation number of chlorine in $HCl{O}_4$ is $+7$