Chemistry - Redox Reactions Question with Solution | TestHub

In ${\text{KO}}_2$, potassium is an alkali metal, which always exhibits an oxidation state of $+1$.

In ${\text{H}}_2{\text{O}}_2$, oxygen is present in a peroxide linkage. Let the oxidation state of oxygen be $x$.
$2(+1)+2x=0\Rightarrow x=-1$

In ${\text{H}}_2{\text{SO}}_4$, let the oxidation state of sulphur be $y$.
$2(+1)+y+4(-2)=0\Rightarrow y=+6$

The oxidation states of the underlined elements are $+1$, $-1$ and $+6$ respectively.

Answer: $+1,-1$ and $+6$