A mixture is prepared using 25.00 ml of a 0.0828 m weak base (pka = 4.576), 25.00 ml of a 0.0621 m weak acid (pka = 3.230) and 1.00 ml of 0.000107 m hin and then diluting to 100.0 ml, where hin is the

A mixture is prepared using 25.00 ml of a 0.0828 m weak base (pka = 4.576), 25.00 ml of a 0.0621 m weak acid (pka = 3.230) and 1.00 ml of 0.000107 m hin and then diluting to 100.0 ml, where hin is the protonated indicator. the absorbance measured at 550 nm in a 5.000 cm cell was 0.1158. the molar absorptivity (ε) values for hin and its deprotonated form in– at 550 nm are 2.26 × 104 m–1cm–1 and 1.53 × 104 m–1cm–1, respectively.