Question

Determine the $pH$ of $0.024M$ hydroxylamine hydrochloride solution. ($K_b$ of hydroxyl amine is $10^{-8}$).

• A. 8.4
• B. 6.2
• C. 3.8
• D. 5.6

Answer 1

Answer: (C)

$HO\stackrel{+}{N}{H}_3+H_{2}O\rightleftharpoons HON{H}_{3}OH+H^{+}$
$K_h=\frac{K_w}{k_b}=\frac{10^{-14}}{10^{-8}}=10^{-6}$
$\left[H^{+}\right]=\sqrt{K_{h}C}$
$=\sqrt{10^{-6}\times 0.024}$
$=1.5\times 10^{-4}$
and $pH=3.8$