Two electrolytic cells containing aqueous solutions of CuSO ₄ and AgNO ₃ respectively are connected in series. If 1.27 ~g of copper is deposited at the cathode of the first cell, what will be the mass of silver deposited at the cathode of the second cell? (Given: Molar mass of Cu = 63.5 ~g ~mol ⁻¹ , Ag = 108 ~g ~mol ⁻¹ )

Step-by-step solution

According to Faraday's Second Law of Electrolysis, when the same quantity of electricity is passed through different electrolytes connected in series, the masses of the substances deposited are proportional to their respective equivalent weights. w_ Ag w_ Cu = E_ Ag E_ Cu The equivalent weight of a metal is its molar mass divided by its valency (n-factor). For Ag in AgNO ₃ , valency = 1 E_ Ag = 108 1 = 108 For Cu in CuSO ₄ , valency = 2 E_ Cu = 63.5 2 = 31.75 Substituting the values into the ratio: w_ Ag 1.27 = 108