Question

Zn amalgam is prepared by elctrtolysis of aqueous `ZnCI_(2)` using 9 gram Hg cathode how much current is to be pased through `ZnCI_(2)` solution for 1000 seconds to prepare a Zn amalagam with 25% by weight ? (atomic masss Zn =65.4 g)
A. Current off `8.85` amp is passed in the process.
B. Current of `5.65` amp is passed in the process
C. Mass of `Zn` in Amalgam is `3gm`
D. Mass of `Zn` in Amalgam is `6gm`.

Answer 1

Correct Answer - A::C::D
Let `x` gm of `Zn` deposit of `9gm` of `Hg`
`%` of `Zn` in Amalgam`=(m_(Zn)xx100)/(m_(Zn)xxm_(Hg))=x/(9+x)xx100=25`
`:.x=3gm`
Eq. of `Zn=(3xx2)/(65.4)`
`(n_(Zn))/1=(n_(e^(-)))/2=Q/(2f)=("it")/(2f)`
Current `i=6/(65.4)xx96500/1000=8.85amp.`