A chemist titrates a 25.00-mL portion of 0.15 M HCl with a 0.20 M solution of KOH. Which of the following options correctly describe how to calculate the pH at the beginning of this titration AND after 15.00 mL of base has been added? Select all that apply.


initial moles of H3O+ = 3.75 x 10-3
initial pH = –log(0.15) = 0.82
[H3O+] after base has been added = 7.5x10−40.0400L