Question

A certain weak base has a Kb of 7.4 x 10⁻⁷. What concentration of this base will produce a pH of 10/15?
a. 2.2 x 10⁻⁸ M
b. 5.0 x 10⁻⁷ M
c. 1.4 x 10⁻⁶ M
d. 3.7 x 10⁻⁵ M