Question

The known per-oxoacids of Sulphur are :
A. $H_2SO_5$
B. $H_2S_2O_9$
C. $H_3S_4O_{12}$
D. $H_2S_2O_8$
E. $H_2S_2O_7$
Choose the correct answer from the options given below :

• A. A, C only
• B. A, D only
• C. A, B, C only
• D. C, D, E only

Hint:

The oxidation state trick is powerful: Assign H as +1 and O as -2. If the central atom's calculated oxidation state exceeds its group valency maximum (like $> +6$ for S, or $> +5$ for P), the molecule almost certainly contains a peroxide ($-O-O-$) linkage!

Answer 1

The Correct Option is B