question_answer

Oxidation number of S in Marshall's acid and dithionic acid are respectively.

A) + 6, + 6          

B) + 6, + 5

C) + 4, + 6          

D) + 5, + 6.

Correct Answer: B

Solution :

Marshall's acid is \[{{H}_{2}}{{S}_{2}}{{O}_{8}}\]. It has one peroxide linkage. 2x + 2 \[\times \] (+1) + 6\[\times \] (-2) + 2 \[\times \] (-1) = 0 for S       for H for oxygen for peroxide oxygen Or   x = + 6 Dithionic acid is \[{{H}_{2}}{{S}_{2}}{{O}_{6}}\] 2x +2(+1) + 6 \[\times \](-2) =0 for S for H       for O Or   x = + 5