Question

Which of the following will have highest pH ?

• A. $0.1MN{H}_{4}Br$
• B. $0.1M\left(N{H}_4\right)S{O}_4$
• C. $0.1MN{H}_{4}N{O}_3$
• D. $0.1M(N{H}_4{)}_{3}P{O}_4$

Answer 1

The correct option is D

$0.1M(N{H}_4{)}_{3}P{O}_4$

In case of (a), (b) and (c) pH < 7 due to cationic $\left(N{H}_4^{+}\right)$ hydrolysis.
In case of $(N{H}_4{)}_{3}P{O}_4,$ both the cation and anion undergo hydrolysis. $pH\approx 7$