Question

Under constant current electrolysis, how many coulombs would be required to reduce 2 mol of Cu2+ to metallic copper? a) 2. b) 48,256. c) 96,500. d) 193,000. e).386,000​

Answer 1

• 1- Equivalent weight of a metal is deposited or reduced at the cathode on electrolysing the metal solution.
• Since Cu2+ is reduced to copper metal the Equivalent weight of the metal= Atomic weight/ Valency.= Mole.wt/2.
• To deposit 1- Equivalent weight of a metal we require= 1- Faraday= 96,500 Coulombs.
• So to reduce or deposit 1- mole of Copper we require = 2- Faraday's.
• Therefore to reduce or deposit 2- moles of copper we require= 2 x2= 4 Faraday's= 4 x 96,500= 386,000 Coulombs.