Question

How to draw the resonating structures of H2SO4 and H2SO5 ???

Answer 1

The Lewis structure of H2SO4 can be made as
           O
            I
H - O - S - O - H
            I
           O

While the resonating structure of H2SO4 is with the double bond. It is improved structure. This structure can be shown in more than 1 way

           O
            I
H - O - S - O - H
           II
           O

or

           O
            II
H - O - S - O - H
            I
           O

And the best structure is where all the formal charges gets zero

           O
            II
H - O - S - O - H
            II
           O

The structure of H2SO5 is

         O
         I I
H O - S - O - OH
         I I
         O