Answer:
7.07
Explanation:
HA = weak acid = 0.053
A+ = conjugate base = 0.045
Ka = 7.2x10^-8
Ka = [H+][A-]/HA
7 2x10^-8 = [H+][0.045]/0.053
[H+] = 7.2x10^-8 x 0.053/0.045
= 8.48x10^-8
PH = -log[H+]
= -log[8.48x10^-8]
PH = -[login.48 + log10^-8]
PH = -0.928 - (-8)log10
= 7.07
