Sum of π -bonds present in peroxodisulphuric acid and pyrosulphuric...

The structure of peroxodisulphuric acid $( {H}_{2}{S}_{2}{O}_{8} )$ is

Each sulphur is having $2\pi$ bonds. Hence, total number of $\pi$-bonds in peroxydisulphuric acid is four.

The structure of pyrosulphuric acid $( {H}_{2}{S}_{2}{O}_{7} )$ is

Each sulphur is having $2\pi$ bonds. Hence, total number of $\pi$-bonds in pyrosulphuric acid is four.

So, sum of $\pi$ bonds present = 4 + 4 = 8