Rules for Assigning Oxidation Number and State

Q. What is the oxidation number of $\text{Mn}$ in ${\text{KMnO}}_4$?

1. 7

Q. What is the oxidation number of oxygen in ${\text{K}}_2\text{O}$?
(Oxidation number of potassium is +1)

1. -2

Q.

Determine the oxidation number of sulphur in $H_{2}S{O}_4$.

1. $+2$

2. $0$

3. $+6$

4. $+4$

Q.

Find the difference in oxidation numbers of sulphur in the $(S{O}_4{)}^{2-}$ ion and $S{O}_3$ compound.

1. 2
2. 0
3. -2
4. 1

Q. The oxidation number of O is in ${\text{OF}}_2$ and in ${\text{H}}_2\text{O}$.

1. -2
2. 2
3. -1
4. 1
5. \N

Q.

What is the oxidation number of phosphorus in phosphoric acid ( $H_{3}P{O}_4$)?

1. +5

2. +3

3. -3

4. -5