pH of mixture containing three moles of NH4OH and one mole of H2SO4 is pKb of  NH4OH = 4.8

The mixture acts like a basic buffer;NH4OH is a monoacidic base;Number of gram equivalents = 3 x 1 = 3H2SO4 is a dibasic acid;Number of gram equivalents = 1 x 2 = 2SA 2. g. eq. +  WB2. g. eq.3 g. eq.1 g.eq.excess   →  Salt2 g. eq.+H2OpOH=pkb+logVsNsVbNb pOH=4.8+log21 pOH=4.8+0.301 pH=14-5.1=8.9