ELECTROLYSIS OF MOLTEN NaCl IS DONE IN A DOWNS CELL OPERATING AT 7.0 VOLTS AND 4.0X10^4A. HOW MUCH Na(s) AND Cl2(g) CAN BE PRODUCED IN 8 HOURS IN SUCH A CELL?

Mass of sodium produced = 2.74 × 10⁵ g of Na

Mass of chlorine produce = 4.24 × 10⁵ g of Cl₂

Explanation:

In the electrolysis of molten NaCl as described above, the quantity of charge used is given by the formula, Q = I × t

Where I isnthe current passed in amperes and t is time in seconds.

Q = 4.0 × 10⁴ A × (8 × 60 × 60) s = 1.152 × 10⁹ C

Equation for the discharge of sodium is; Na+ + e- ---> Na (s)

One mole of electrons is required to discharge one mole of Na

One mole of electron = 1 faraday = 96500 C

One mole of Na has a mass of 23 g

96500 C produces 23 g of Na

1.152 × 10⁹ C will produce 23 g × 1.152 × 10⁹ C / 96500 C = 2.74 × 10⁵ g of Na

Equation for the discharge of chlorine gas is; 2 Cl- ---> Cl₂(g) + 2e-

Two mole of electrons are required to discharge one mole of chlorine gas

Two moles of electron = 2 faraday = 2 × 96500 C = 193000

One mole of Cl₂ has a mass of 71 g

193000 C produces 71 g of Cl₂

1.152 × 10⁹ C will produce 71 g × 1.152 × 10⁹ C / 193000 C = 4.24 × 10⁵ g of Cl₂

The neutralization of the base with an acid will result to the formation of salt and water. In this case, a mole of strong acid will have one halide that will react with the Na atom. Since there are two Na atoms in each of the molecule of Na2HPO4, this will need 2 halide atoms.