Redox Reactions And Electrochemistry Ques 323
Question: An electric current is passed through silver nitrate solution using silver electrodes. 10.79 g of silver was found to be deposited on the cathode if the same amount of electricity is passed through copper sulphate solution using copper electrodes, the weight of copper deposited on the cathode is [Kerala PMT 2004]
Options:
A) 6.4 g
B) 2.3 g
C) 12.8 g
D) 1.6 g
E) 3.2 g
Show Answer
Answer:
Correct Answer: E
Solution:
Number of equivalents of silver formed = Number of equivalents of copper formed.
In $ AgNO_3,\ Ag $ is in +1 oxidation state.
In $ CuSO_4,\ Cu $ is in +2 oxidation state.
Equivalent weight of Ag = $ \frac{108}{1}=108 $
Equivalent weight of Cu $ =\frac{63.6}{2}=31.8 $ $ \frac{M_1}{M_2}=\frac{E_1}{E_2} $ ; $ \frac{10.79}{M_{Cu}}=\frac{108}{31.8} $
$ M_{Cu}=\frac{10.79\times 31.8}{108}=3.2\ gm $ .
