Q4 / 150 · MHT CET 2026 (16 April Shift 1) · Chemistry
What is the oxidation number of oxygen in $\text{KO}_2$ ?
- A$-2$
- Correct answerB$-1/2$
- C$-1$
- D$+2$
Solution
Let the oxidation number of oxygen in $\text{KO}_2$ be $x$.
Potassium is an alkali metal, so its oxidation state is always $+1$ in its compounds.
The sum of oxidation states of all atoms in a neutral molecule is zero.
$+1 + 2x = 0$
$2x = -1$
$x = -1/2$
The oxidation number of oxygen in $\text{KO}_2$ is $-1/2$.
Answer: $-1/2$
Potassium is an alkali metal, so its oxidation state is always $+1$ in its compounds.
The sum of oxidation states of all atoms in a neutral molecule is zero.
$+1 + 2x = 0$
$2x = -1$
$x = -1/2$
The oxidation number of oxygen in $\text{KO}_2$ is $-1/2$.
Answer: $-1/2$
Hence, the correct answer is option: 'B'.