Question

the pH of 0.5 m h 2 S o4 IS

Answer 1

 If we you have a 0.5M solution of H2SO4, and we work on the basis that it ionises completely, then we will have 0.5*2 = 1.00 moles H+ (or H3O+) ions per litre. 
Therefore [H+] = 1.00 
pH = -log[H+] 
pH = -log 1.00 
pH = 0