1. Tardigrade
  2. Question
  3. Chemistry
  4. The pH of an aqueous solution of a 1× 10-7M solution of HCl will be

Question Error Report

Thank you for reporting, we will resolve it shortly

Back to Question

Q. The $ pH $ of an aqueous solution of a $ 1\times {{10}^{-7}}M $ solution of $ HCl $ will be

Rajasthan PMTRajasthan PMT 2011

Solution:

$ [{{H}^{+}}] $ ions from $ HCl $ acid $ =1\times {{10}^{-7}}M $ Here, $ [{{H}^{+}}] $ ions from $ {{H}_{2}}O={{10}^{-7}}M $ cannot be neglected in comparison to $ {{10}^{-7}}M[{{H}^{+}}] $ ions from $ HCl $ . $ \therefore $ Total $ [{{H}^{+}}]={{10}^{-7}}+{{10}^{-7}} $ $ ={{10}^{-7}}(1+1) $ $ =2\times {{10}^{-7}}M $ $ pH=-\log [{{H}^{+}}] $ $ =-\log [2\times {{10}^{-7}}] $ $ =-[\log 2+\log {{10}^{-7}}] $ $ =-(0.3010-7) $ $ =6.6989 $ $ \therefore $ $ pH $ of a solution of $ 1\times {{10}^{-7}}M $ is slightly less than 7.