A metal object is to be gold-plated by an electrolytic procedure using aqueous AuCl₃ electrolyte.Calculate the number of moles of gold deposited in 3.0 min by a constant current of 10.A.

Question

Quizplus · Accepted Answer

The amount of metal deposited during electrolysis is directly proportional to the charge passing through the cell. Charge (C) = Current (A) x Time (s) In this case, the current is 10 A, and the time is 3 min = 180 s. Charge = 10 A x 180 s = 1800 C The amount of charge passing through the cell is equal to the amount of charge transferred by the gold ions. Charge (C) = Faraday constant (F) x moles of gold (mol) x valence The valence of gold in AuCl₃ is +1, so the valence factor is 1. Faraday constant = 96500 C/mol Rearranging the equation: mol = Charge (C) / (Faraday constant x valence) Substituting the values: mol = 1800 C / (96500 C/mol x 1) = 0.0187 mol Therefore, the number of moles of gold deposited in 3 mins is 0.0187 mol or 6.2 × 10^-3 mol (rounded to three significant figures). Thus, the correct answer is option A).

A Metal Object Is to Be Gold-Plated by an Electrolytic