How many grams of copper metal can be deposited from Cu²⁺(aq) when a current of 2.50 A is run for 4.65 h? (F = 96,500 C/mol)

Answer 1

Cu²⁺(aq) + 2e- ==> Cu(s)

Find out how many coulombs were supplied and then we can find moles of electrons transferred.

1 amp = 1 coulomb/second (C/s)

2.50 amps = 2.50 C/s

4.65 hr x 60 min/hr x 60 sec/min = 16,740 s

2.50 C/s x16,740 s = 41,850 C

Now convert this to moles of electrons:

41,850 C x 1 mol e- / 96,500 C = 0.433 moles electrons

How many moles of Cu is this equivalent to?

0.433 mol e- x 1 mol Cu(s) / 2 mol e- = 0.2165 moles Cu

grams Cu = 0.2165 mol x 63.5 g Cu/mol = 13.7 g Cu