Question

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?

Answer 1

Answer:

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