Redox Reactions And Electrochemistry Ques 737
Question: Zn-Hg is prepared by electrolysis of aqueous $ ZnCl_2 $ using Hg cathode (9g). How much current is to be passed through $ ZnCl_2 $ solution for 1000 s to prepare a Zn-Hg with 25% Zn by weight (Zn = 65.4):
Options:
A) 5.6 A
B) 7.2 A
C) 8.85 A
D) 11.2 A
Show Answer
Answer:
Correct Answer: C
Solution:
[c] Let x gram of Zn deposited on 9 g of Hg % of Zn in amalgam $ =\frac{x}{9+x}\times 100=25 $
$ \therefore $ $ x=3g $ Eq. of $ Zn=\frac{3\times 2}{65.4} $ $ Current,=\frac{6}{65.4}\times \frac{96500}{100}=8.85A $
