π = iMRT
π = osmotic pressure = 90.2 atm (presumably atm)
i = van't off factor = ? for H2SO4
M = molarity = 1
R = gas constant = 0.0821 L-atm/mol-K
T = temperature in K = 500K
Solving for i: i = π/MRT = (90.2)/(1)(0.0821)(500) = 2.197
2 of the 2.197 can be accounted for by H+ and HSO4-. The remaining 0.197 would be from H+ and SO42-.
H2SO4 ==>H+ + HSO4- K1 = infinite and thus i = 2 for H+ and HSO4-
[HSO4-] = 1 M since 100% dissociation of H2SO4
HSO4- ==> H+ + SO42- K2 = ?
K2 = [H+][SO42-]/[HSO4-] = (0.0985)(0.0985)/1 = 9.7x10-3