A jeweler needs to electroplate gold (atomic mass 196.97 u)onto a bracelet.He knows that the charge carriers in the ionic solution are gold ions,and has calculated that he must deposit 0.20 g of gold to reach the necessary thickness.How much current does he need to plate the bracelet in 3.0 hours? (Avogadro's number is 6.02 × 10²³. )

Question

Quizplus · Accepted Answer

To find the current, first calculate the moles of gold: 0.20 g / 196.97 g/mol = 0.001015 mol. Each mole of gold requires 1 mole of electrons (1 Faraday = 96485 C/mol). Total charge needed = 0.001015 mol × 96485 C/mol = 97.9 C. Current = charge/time = 97.9 C / (3 × 3600 s) = 0.0091 A or 9.1 mA.

A Jeweler Needs to Electroplate Gold (Atomic Mass 196