Question

How many Faraday of electricity are required to liberate by electricity of 4g of copper

Answer 1

Molecular weight of copper $=63.55$

g/mol of 4g of copper $=$ $4\over 63.55$

$=0.063$ moles

$CU^{2+}+2e^{-} -CU$

$0.63$ moles of copper will require $0.063*1 =0.063$ faradays of electricity.