A) 4.30
B) 5.15
C) 7.0
D) 8.75
Correct Answer: B
Solution :
The hydrolysis reaction is \[NH_{4}^{+}+{{H}_{2}}O\rightleftharpoons N{{H}_{4}}OH+{{H}^{+}}\] \[{{k}_{h}}=\frac{[N{{H}_{4}}OH][{{H}^{+}}]}{[NH_{4}^{+}]}=\frac{{{K}_{w}}}{{{K}_{b}}}=5\times {{10}^{-10}}\] \[5\times {{10}^{-10}}=\frac{{{[{{H}^{+}}]}^{2}}}{c}\{\therefore [N{{H}_{4}}OH]=[{{H}^{-}}]\}\] \[[{{H}^{+}}]=\sqrt{5\times {{10}^{-10}}\times 2\times 0.05}\] \[[{{H}^{+}}]=7\times {{10}^{-6}}\Rightarrow pH=5.15\]
You need to login to perform this action.
You will be redirected in
3 sec
