Question

Oxidation number of sulphur in Caros acid is

• A. 6
• B. 4
• C. 8
• D. 7

Answer 1

Answer: (A)

Caros acid is ${\text{H}}_{\text{2}}\text{S}{\text{O}}_{\text{5}}\text{.}$ It has a peroxide linkage, so, oxidation of S is calculated as
Let the oxidation state of S is $x.$ ${\text{H}}_{\text{2}}\text{S}{\text{O}}_{\text{5}}$ (one peroxide bond) $+2+x+3(-2)+1(-2)=0$ $2+x-6-2=0$ $x-6=0$ $x=+6$