HOMEWORK 2 Analytical Chemistry

Analytical chemistry Semester II, 2020-2021 HOMEWORK # Due date: 1/4/2021 (20 pts) The base B has pKb = 5.00 (a) What is the value of pKa for the acid BH+? (b) At what pH is [BH+] =[B]? (c) Which is the principal species at pH 7.00: B or BH+? (d) What is the quotient [B]/[BH+] at pH 12.00? (40 pts) Calculate the pH of a solution prepared by mixing 0.0800 mol of chloroacetic acid (ClCH2COOH) with a pKa = 2.86, plus 0.0400 mol of sodium chloroacetate (ClCH2COO –Na+) in 1.00 L of water (a) First the calculation by assuming that the concentrations of HA and A- equal their formal concentrations (b) Then, the calculation, using the real values of [HA] and [A-] in the solution by assuming that at equilibrium, [OH-]