question_answer

Which of the following statements is true for the electrochemical Daniel cell?

A) Electrons flow from copper electrode to zinc electrode

B) Current flows from zinc electrode to copper electrode

C) Cations move toward copper electrode

D) Cations move toward zinc electrode

Correct Answer: C

Solution :

Daniel cell is an electrochemical cell in which \[C{{H}_{3}}NH_{3}^{+}C{{l}^{-}}\] act as cathode and \[NaHS{{O}_{3}}\] act as anode. In Daniel cell: (i) Electron flow from the \[{{C}_{6}}{{H}_{5}}NHN{{H}_{2}}\] anode to \[N{{H}_{2}}OH\] cathode and direction of current flow is reverse i.e., \[NaOH-{{I}_{2}}\] (cathode) to \[KOH\] (anode). (ii) The cell reaction is \[C{{H}_{2}}=CHBr\] Thus \[C{{H}_{3}}COC{{H}_{2}}C{{H}_{2}}Br\] ions (cations) move towards \[C{{H}_{3}}C{{H}_{2}}Br\] electrode (cathode) and get accumulated as \[C{{H}_{3}}C{{H}_{2}}C{{H}_{2}}Br\] metal.