Question

Calculate the volume of hydrogen produced during the electrolysis of dilute sulphuric acid if you use a current of 1A for 15minutes?

Answer 1

Answer:

The volume of hydrogen gas produced is 0.104 L or 104 mL

Explanation:

In the electrolysis of dilute sulphuric acid, hydrogen gas is produced at the cathode while oxygen gas is given off at the anode in a ratio of 2:1.

At the cathode, the half reaction occurring is given as: 4H⁺(aq) + 4e⁻ ---> 2H₂(g)

From the equation of reaction, four moles of electrons are required to produce 2 moles of hydrogen gas at the cathode. Therefore, 2 moles of electrons will produce 1 mole of hydrogen gas.

1 mole of electron = 1 F = 96500 C

2 moles of electron = 193000 C

During the electrolysis experiment above, quantity of charged used, q = current(A) * time (s)

Q = 1 * 15 * 60 = 900 C

193000 C (2 moles of electron)of electricity produces 1 mole of hydrogen gas

900 C of electricity will produce 900 * 1 mole /193000 of hydrogen = 0.00466 moles of hydrogen

Molar volume of a gas at STP = 22.4 L

0.00466 moles of hydrogen occupies a volume of 0.00466 * 22.4 L = 0.104 L or 104 mL

Therefore, volume of hydrogen gas produced is 0.104 L or 104 mL