question_answer 31)

Three electrolytic cells A, B and C containing solution of ZnSO4, AgNO3 and CuSO4, respectively are connected in series. A steady current of 1.5 amperes was passed through them until 1.45 g of silver deposited at the cathode of cell it. How long did the current flow? What mass of copper and of zinc were deposited? (Atomic mass : Zn = 65.4u, Ag = 108u,  Cu = 63.54).

Answer:

Cell B contains AgNO3 and reaction may be represented as: AgNO3 Ag+ + NO3? According to the equation, 108 g of silver is deposited by = 96500 C 1.45 g silver is deposited by Now,     Q = It or            The weight of copper and zinc can be calculates by using Faraday's second law of electrolysis. In Cells B and C or or Wt. of copper deposited = 0.426 g Similarly in Cells A and B. or  Wt. of zinc deposited = 0.440 g