JEE Main & Advanced Chemistry Electrochemistry / विद्युत् रसायन Question Bank Topic Test - Electrochemistry

Zn-Hg is prepared by electrolysis of aqueous \[ZnC{{l}_{2}}\] using Hg cathode (9g). How much current is to be passed through \[ZnC{{l}_{2}}\] solution for 1000 s to prepare a Zn-Hg with 25% Zn by weight (Zn = 65.4):

A) 5.6 A

B) 7.2 A

C) 8.85 A

D) 11.2 A

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 \[Zn=\frac{3\times 2}{65.4}\]

\[\text{Current}\,=\frac{6}{65.4}\times \frac{96500}{100}=8.85A\]