Trimethylamine (C3H9N) is a weak base (pKb = 4.19) with a fishy odour. In a titration of 250.0 mL of aqueous trimethylamine solution, 23.6 mL of 0.974 M HCl was required to reach the equivalence point.
a) Calculate the pH of the solution at the equivalence point of the titration.
b) Briefly explain which indicator, bromocresol purple (pKa = 6.3; from yellow to purple) or thymolphthalein (pKa= 10.0; from colourless to blue), would be better for use in this titration