Q. Calculate the oxidation number of Sulphur in K_{2}S_{2}O_{3} and SOCl_{2}.

Let the oxidation number of S in K_{2}S_{2}O_{3} be x.

also, we know that the oxidation number of potassium is +1

and the oxidation number of oxygen is -2.

Applying the rule,

(+1) × 2 + (x) × 2 + (-2) × 3 = 0

+2 + 2x – 6 = 0

2x – 4 = 0

2x = +4

x = +2

**Hence the oxidation number of Sulphur in K _{2}S_{2}O_{3} is +2.**

Similarly, let the oxidation number of sulphur in SOCl_{2} is y.

then according to the rule,

y + (-2) × 2 + (-1) × 2 = 0

y – 4 -2 = 0

y-6 = 0

y = +6

**Hence the oxidation number of sulphur in SOCl _{2} is + 6.**