Question

Oxidation number of potassium in $K_{2}O,K_2{O}_2,K{O}_2$ respectively, are :

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• A. $+2,+1\text{and}+\frac{1}{2}$
• B. $+1,+2\text{and}+4$
• C. $+1,+1\text{and}+1$
• D. $+1,+4\text{and}+2$

Answer 1

The correct option is C $+1,+1\text{and}+1$

Potassium is an element which belongs to alkali metal group. All alkali metals show only one oxidation state,i.e., $+1$. Therefore, potassium in all its oxides shows +1 oxidation state. This can also be shown as,
Oxidation number in $\stackrel{+1}{K_2}\stackrel{-2}{O}$

Hence, oxidation number of Potassium in $K_{2}O$ is $+1$

Oxidation number in $\stackrel{+1}{K_2}\stackrel{-1}{O_2}$

Hence, $O.N.$ of Potassium in $K_2{O}_2$ is $+1$

$O.N.\text{in})\stackrel{+1}{K}\stackrel{-0.5}{O_2}$

Hence, $O.N\text{of}K\text{in}K{O}_2\text{is}+1)$