Question

A weak acid HA after treatment with 12 ml of 0.1 M strong base BOH has pH = 5. At the endpoint, the volume of the same base required is 13.2 ml. Ka of acid is:
a) 2.5 × 10⁻⁶
b) 5.0 × 10⁻⁶
c) 1.0 × 10⁻⁵
d) 2.0 × 10⁻⁵