Question
Question: \(K_{a}\)for \(CH_{3}COOH\) is \(1.8 \times 10^{- 5}\)and \(K_{b}\) for \(NH_{4}OH\) is \(1.8 \times...
Kafor CH3COOH is 1.8×10−5and Kb for NH4OH is 1.8×10−5The pH of ammonium acetate will be.
A
7.005
B
4.75
C
7.0
D
Between 6 and 7
Answer
7.0
Explanation
Solution
: CH3COONH4 is a salt of weak acid (CH3COOH) and weak base (NH4OH).
pH=7+21(pKa−pKb)
pKa=−logKa=−log(1.8×10−5)=4.74
pKb=−logKb=−log(1.8×10−5)=4.74
pH=7+21(4.74−4.74)=7.0