2. Sample Papers
  3. NEET

NEET Sample Paper NEET Sample Test Paper-85

  • question_answer
    Aluminium displaces hydrogen from acids but copper does not. A galvanic cell prepared by combining \[Cu/C{{u}^{2+}}\]and\[Al/A{{l}^{3+}}\]has an e.m.f of 2.0 V at \[298{}^\circ K.\] If the potential of copper electrode is \[+0.34\,\,V\] that of aluminium is

    A) \[+1.66\,\,V\]    

    B)        \[-1.66\,\,V\]

    C) \[+2.34\,\,V\]    

    D)        \[-2.3\,\,V\]

    Correct Answer: B

    Solution :

    [b] The given statement explains that Al is placed above Cu in E.C.S. hence it can reduce Cu from its salt solution (reduction). Thus Al acts as a reducing agent now, Given : electrode potential of copper \[({{E}^{0}}_{cell})=+\,0.34\,\,V\] e.m.f of cell\[=2\,\,V\] We know that, emf of a galvanic cell \[({{E}^{0}}\,\,cell)\] = electrode potential of Cu (cathode) - electrode potential of Al (anode) \[2.0=0.34-{{E}^{0}}_{A1}\] \[{{E}^{0}}_{A1}=0.34-2.00=-1.66\,\,V\] Hence, electrode potential of Al is \[-1.66\,\,V.\] Option [b] is correct.


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