An electrolytic cell plates nickel onto a metal strip using a constant current of…
CHEMISTRY · Multi-part · AP · Chemistry · Thermodynamics and Electrochemistry · Thermodynamics and Electrochemistry
Problem
An electrolytic cell plates nickel onto a metal strip using a constant current of 5.00 A for 2.00 h at a cell voltage of 3.10 V. The mass of nickel actually deposited is 9.80 g. (Molar mass Ni = 58.7 g mol⁻¹; reaction: Ni²⁺(aq) + 2 e⁻ → Ni(s); Δ₍f₎G° for this reaction = –52.6 kJ mol⁻¹.)
(a) Calculate the electrical energy, in kJ, supplied to the cell during the plating run.
(b) Determine the theoretical mass of nickel that should be deposited under these conditions.
(c) Using the actual mass deposited, calculate the energy efficiency of the cell, defined as 100 × (chemical energy stored in the nickel deposited)/(electrical energy supplied).