Which of the following are peroxoacids of sulphur?

1.  H2SO5  and  H2S2O82.  H2SO5  and  H2S2O73.  H2S2O7 and  H2S2O84.  H2S2O6 and  H2S2O7

 

Hint: Peroxoacid contains -O-O- linkage.

 
Peroxoacids of sulphur must contain one -O-O- linkage.  H2SO5  and  H2S2O8 are the compound that contains a peroxy linkage. The structures of both the compound are as follows:
 
The structures of the other compounds are as follows: