Question
Chemistry Question on Oxidation Number
The oxidation states of sulphur in the anions SO32−,S2O42− and S2O62− follow the order -
A
S2O42−<S2O62−<SO32−
B
S2O62−<S2O42−<SO32−
C
S2O42−<SO32−<S2O62−
D
SO32−<S2O42−<S2O62−
Answer
S2O42−<SO32−<S2O62−
Explanation
Solution
Oxidation state of S in SO32−
\hspace19mm x + ( - 2 × 3 ) = - 2
\hspace19mm x = + 6 - 2 = + 4
Oxidation state of S in S2O42−
\hspace19mm 2 x 4- (- 2 × 4) = - 2
\hspace19mm 2x = + 8 - 2 = + 6
\hspace19mm x=2+6=+3
Oxidation state of S in S2O62−
\hspace19mm 2 x 4 - (- 2 x× 6) = - 2
\hspace19mm 2x = 4 - 12 - 2 = 10
\hspace19mm x = 210=−5
Hence, increasing order of oxidation states of S is
S2O42−<SO32−<S2O62−