A) 5
B) 9
C) 7
D) 8
Correct Answer: B
Solution :
\[HA+O{{H}^{-}}{{H}_{2}}O+{{A}^{-}}\] \[K=\frac{[{{A}^{-}}]}{[HA]O{{H}^{-}}]}\] \[HA{{H}^{+}}+{{A}^{-}}\] \[{{K}_{a}}=\frac{[{{H}^{+}}][{{A}^{-}}]}{[HA]}\] \[\frac{{{K}_{a}}}{K}=[{{H}^{+}}][O{{H}^{-}}]={{K}_{w}}\] Or \[{{K}_{a}}={{K}_{2}}K={{10}^{-14}}\times {{10}^{9}}={{10}^{-5}}\] \[p{{K}_{a}}=5\] \[{{A}^{-}}\]solution is alkaline due to hydrolysis \[\therefore \]\[pH=7+\frac{p{{k}_{a}}}{2}+\frac{\log C}{2}=2+\frac{5}{2}+\frac{\log 0.1}{2}=9\]
You need to login to perform this action.
You will be redirected in
3 sec
