CMC Medical CMC-Medical VELLORE Solved Paper-2015

  • question_answer
    The pH of a mixture when a 60 mL solution of pH = 1 is mixed with 60 mL of pH = 2, is

    A)  0.56                      

    B)  1.76

    C)  1.18                      

    D)  2.06

    E)  1.56

    Correct Answer: C

    Solution :

                    For \[pH=1,\,\,[{{H}^{+}}]={{10}^{-1}}M\] For         \[pH=2\,[{{H}^{+}}]={{10}^{-2}}M\] \[{{M}_{1}}{{V}_{1}}+{{M}_{2}}{{V}_{2}}={{M}_{R}}({{V}_{1}}+{{V}_{2}})\] \[{{10}^{-1}}\times 60+{{10}^{-2}}\times 60={{M}_{R}}(100)\] \[0.6+0.06={{M}_{R}}(100)\] \[{{M}_{R}}=\frac{0.66}{100}=6.6\times {{10}^{-2}}M\] \[{{M}_{R}}=\]Resultant molarity of \[{{H}^{+}}\]ions \[pH=-\log 6.6\times {{10}^{-2}}\] \[=-\,[(\log \,6.6)-2log10]=-\,[0.819-2]\] \[=-\,[-1.18046]=1.18\]


You need to login to perform this action.
You will be redirected in 3 sec spinner