Answer
Please see the work below.
Work Step by Step
We know that
A. $K_b=\frac{K_w}{K_a}$
$K_b=\frac{1.0\times 10^{-14}}{4.5\times 10^{-4}}=2.22\times 10^{-11}$
B . We know that
$K_a=\frac{K_w}{K_a}$
$K_a=\frac{1.0\times 10^{-14}}{1.4\times 10^{-9}}=7.14\times 10^{-6}$
