. What is the quantity of electricity in Coulombs required to produce 4.8 g of Mg from molten MgCl2? How……………

Question 36:. What is the quantity of electricity in Coulombs required to produce 4.8 g of
Mg from molten MgCl2? How much Ca will be produced if the same amount of electricity was passed through molten CaCl2? (Atomic mass of
Mg = 24 u, atomic mass of Ca = 40 u).

The correct answer is -Mg2+ + 2e- à Mg
1 mole of magnesium ions gains two moles of electrons or 2F to form 1 mole of Mg
24 g Mg requires 2 F electricity
4.8 g Mg requires 2 x4.8/24 = 0.4 F = 0.4 x96500 = 38600C (1)
Ca2+ + 2e- Ca
2 F electricity is required to produce 1 mole =40 g Ca
0.4 F electricity will produce 8 g Ca