pH = pKa + log([A-]/[HA]) (base) HONH2 + H2O (acid) HONH3+ + OH- so, pH = pKa + log([HONH2]/[HONH3+]) pH = 1.1 E-8 + log(0.500/0.500) = 1.1 E-8 + 0 = 1.1 E-8 Solution pH = pKa + log([A-]/[HA]) (base) HONH2 + H2O (acid) HONH3+ + OH- so, pH = pKa + log([HONH2]/[HONH3+]) pH = 1.1 E-8 + log(0.500/0.500) = 1.1 E-8 + 0 = 1.1 E-8.