Analytical Chem istry - DePauw University

Chapter 6 Equilibrium Chemistry279Clearly this assumption is acceptable. Our second assumption is that theconcentration of NH 3 is scientifically greater than the concentration ofNH 4 + . Using our simplified charge balance equation, we find that[ NH ] = [ OH ] = 935 . × 10+ − −44Because the concentration of NH + 4 is 1.9% of C NH , our second assumptionalso is reasonable. Given that [H 3 O + ] is 1.07 × 10 –11 , the pH3is 10.97.Click here to return to the chapter.Practice Exercise 6.11In solving for the pH of 0.10 M alanine, we made the following threeassumptions.Assumption One: [ HL] >> [ HL + ] + [ L− ]Assumption Two: K K