Why is 
for H2SO4in water?
H2SO4 is dibasic acid (two replacable H+ ions) . In aqueous solution it dissociates in two steps as follows:
H2SO4 + H2O ⇒ H3O+ + HSO4 | (Ka1 = very large) |
HSO4 + H2O ⇒ H3O+ + SO42 | (Ka2 = 1.2 x 10–2) |
The formula for dissociation constants are:
The neutral H2SO4 molecule has more tendency to lose a proton (H+) than the Lowry-Bronsted base (which can donate electron i.e. accept a proton H+) HSO4-. This is because a neutral has a much higher tendency to lose a proton than the negatively charged. Thus, the former is a much stronger acid than the latter.
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