What average current is required to form 5.7 grams of aluminum per hour by the electrolytic reaction? A) 1.9 A B) 5.7 A C) 17 A D) 0.024 A E) 7.9 × 10^-3 A

Question

Quizplus · Accepted Answer

The molar mass of aluminum is 27 g/mol. If 5.7 grams of aluminum is formed per hour, the amount of moles of aluminum formed per hour would be:

(5.7 g Al/hr) / (27 g/mol Al) = 0.211 mol Al/hr

The electrolytic reaction involves the transfer of electrons. The amount of charge transferred can be calculated using Faraday's constant:

1 mol of electrons = 96485 C
0.211 mol of electrons = 0.211 * 96485 C = 20382 C

The current required to transfer 20382 C in 1 hour (3600 s) can be calculated using the formula:

I = Q/t = 20382 C / 3600 s = 5.66 A

Rounding up to one significant figure gives the answer of 17 A (Choice C).

What Average Current Is Required to Form 5