Question

Calculate the pH of the resulting solution if 21.0 mL of 0.210 M HCl(aq) is added to
a) 26.0 mL of 0.210 M NaOH(aq)
b) 31.0 mL of 0.260 M NaOH(aq)

Answer 1

moles HCl = M x L = ??
moles NaOH = M x L = ??
Which is in excess.
delta moles = (H^+) or (OH^-) depending upon which in in excess, then
M = moles/total volume in L.
Finally, pH = =log(H^+) or pOH= -log(OH^-)

Answer 2

13.56