According to Faraday’s first law of electrolysis, the mass of a substance getting deposited at the cathode is proportional to the quantity of charge passing through the solution.
`m prop Q`
`m prop I*t`
For copper, Z = Eqv. Wt./Faraday=31.75/96500
Plugging in the values,
Therefore, the maximum mass of copper that could be deposited by passing a current of 2 amp. for 20 min. through a CuSO4 solution is 0.79 g.