Exercise 2 | Electrochemistry

General Chemistry 3 - Exercise 2

What mass of nickel could be electroplated from a solution of nickel(II) chloride by a current of 0.480 A flowing for 12 hours?

Faraday’s law of electrolysis:

m = ItF x Mνe 

m = mass deposited as Ni (in g)
I = current (in A)
t = time (in s) ⇒ 12 hours = 4.32 x 104 s
F = Faraday’s constant = 96485 C.mol-1
M = molar mass (in g.mol-1) ⇒ MNiCl2 = 129.6 g.mol-1
νe = stoichiometric coefficient of the electrons in the half reaction equation

 

Half reaction: Ni2+ (aq) + 2 e- → Ni (s)      [νe = 2]

 

m = ItF x Mνe 

m = 0.48 × 4.32 × 10496485 × 129.62

m = 6.31 g of NiCl2