Equilibrium Question 489
Question: $ {10^{-6}}MHCl $ is diluted to 100 times. Its $ pH $ is [CPMT 1984]
Options:
A) 6.0
B) 8.0
C) 6.95
D) 9.5
Show Answer
Answer:
Correct Answer: C
Solution:
$ {10^{-6}},M,HCl={10^{-8}}M,[{H^{+}}] $ . Also from $ H_2O $
$ [{H^{+}}]={10^{-7}}M $ Total $ [{H^{+}}]={10^{-7}}+{10^{-8}}={10^{-7}}[1+0.1] $
$ ={10^{-7}}[1.1] $ Hence $ pH=7-0.0414=6.96 $ .
