In the electrolysis of water, 2H2O → 2H2 + O2, if the volume of oxygen produced was 8 mL, what would be the volume of hydrogen produced?

a. 4 mL

b. 8 mL

c. 16 mL

d. 24 mL

16ml

Explanation:

2H2O → 2H2 + O2

2mol 2mol 1mol

volume of oxygen produced = 8ml

1mole of a gas contains 22.4dm³

8ml will be equal to 8ml/22.4dm³ number of moles of oxygen gas

Using the stoichoimetric co-efficients; 2moles of H2 and 1mol of Oxygen were produced

so number of moles of hydrogen will be [ (2*8ml) / 22.4dm³moles

but 1mol contains 22.4dm³

[ (2*8ml) / 22.4dm³moles will contain x

cross multiply;

x = (2*8ml) mol/22.4dm³ * 22.4dm³/1mol

x=16ml

simply put; using the stochoimetric coefficients if 2moles of H2 correspond to 1mol of O2, thus 16ml of H2 will correspod to 8ml of O2.