2. Questions Bank
  3. NEET
  4. Chemistry
  5. Electrochemistry / विद्युत् रसायन

NEET Chemistry Electrochemistry / विद्युत् रसायन Question Bank Self Evaluation Test - Electrochemistry

  • question_answer
    A battery is constructed of Cr and \[N{{a}_{2}}C{{r}_{2}}{{O}_{7}}\]. The unbalanced chemical equation when such a battery discharges is following \[N{{a}_{2}}C{{r}_{2}}{{O}_{7}}+Cr+{{H}^{+}}\to C{{r}^{3+}}+{{H}_{2}}O+N{{a}^{+}}\] If one Faraday of electricity is passed through the battery during the charging, the number of moles of \[C{{r}^{\text{3+}}}\] removed from the solution is

    A) \[\frac{4}{3}\]                          

    B) \[\frac{1}{3}\]

    C) \[\frac{3}{3}\]                          

    D) \[\frac{2}{3}\]

    Correct Answer: C

    Solution :

    [c] Reduction half reaction: \[C{{r}_{2}}O_{7}^{2-}+6{{e}^{-}}~+14{{H}^{+}}\xrightarrow{{}}2C{{r}^{3+}}+7{{H}_{2}}O\] Oxidation half reaction: \[Cr\xrightarrow{{}}C{{r}^{3+}}+3{{e}^{-}}\] Overall reaction: \[C{{r}_{2}}O_{7}^{2-}+Cr~+14{{H}^{+}}+3{{e}^{-}}\xrightarrow{{}}3C{{r}^{3+}}+7{{H}_{2}}O\] 3F of electricity = 3 moles of \[C{{r}^{3+}}\] 1F of electricity \[=\frac{3}{3}\] moles of \[C{{r}^{3+}}\]


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