2. Solved Papers
  3. J & K CET Medical

J & K CET Medical J & K - CET Medical Solved Paper-2000

  • question_answer
    At 298 K, the standard reduction potentials for the following half reactions are given as:
    \[Z{{n}^{2+}}+2{{e}^{}}\xrightarrow{{}}Zn(s)\]                         \[\,0.762\]
    \[C{{r}^{3+}}(aq)+3{{e}^{}}\xrightarrow{{}}Cr(s)\]                                 \[\,0.740\]
    \[2{{H}^{+}}(aq)+2{{e}^{}}\xrightarrow{{}}{{H}_{2}}(g)\]                      \[0.00\]
    \[F{{e}^{3+}}(aq)+3{{e}^{}}\xrightarrow{{}}Fe(aq)\]                   \[+\,0.770\]
    The strongest reducing agent is:

    A)  Zn (s)                                   

    B)  H (s)

    C)  Cr (s)                                   

    D)  Fe (s)

    Correct Answer: A

    Solution :

    \[Z{{n}^{2+}}+2{{e}^{-}}\xrightarrow{{}}Zn;\] \[{{E}^{o}}=-\,0.762\]
    \[C{{r}^{3+}}+3{{e}^{-}}\xrightarrow{{}}Cr;\] \[{{E}^{o}}=-\,0.740\]
    \[2{{H}^{+}}+2{{e}^{-}}\xrightarrow{{}}{{H}_{2}};\] \[{{E}^{o}}=0.00\]
    \[F{{e}^{3+}}+3{{e}^{-}}\xrightarrow{{}}Fe;\] \[{{E}^{o}}=+0.770\]
    The substances which have lower reduction potential are stronger reducing agents. Here, the reduction potential of zinc is lowest hence, it is the strongest reducing agent.


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