Chhattisgarh PMT Chhattisgarh PMT Solved Paper-2007

  • question_answer
    In a first-order reaction \[A\xrightarrow{{}}B,\]if fc is rate constant and initial concentration of reactant A is \[0.5\text{ }M\]then the half-life is

    A)  \[\frac{In\,\,2}{k}\]                       

    B)  \[\frac{0.693}{0.5}\]

    C)  \[\frac{\log \,2}{2k}\]                                   

    D)  \[\frac{\log \,2}{k\sqrt{0.5}}\]

    Correct Answer: A

    Solution :

    For first order reaction \[k=\frac{2.303}{t}\log \frac{a}{(a-x)}\]                 \[\Rightarrow \]               \[{{t}_{1/2}}=\frac{2.303}{k}\log \frac{a}{(a-a/2)}\]                 \[\Rightarrow \]               \[{{t}_{1/2}}=\frac{2.303}{k}\log \,2\]                 \[\therefore \]  \[{{t}_{1/2}}=\frac{\operatorname{In}\,2}{k}\]


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