Question

On analyzing an impure sample of sodium chloride, the percentage of chlorine was found to be 45.5. what is the percentage of pure sodium chloride in the sample? [hots]

Answer 1

Because the number of mols of hydrogen resulted from the electrolysis is always double, and each mol of gas occupies the same volume (1 mol of gas = 22,4 l in STP)

2H2O—-> 2H2 + O2

2 mol H2O => 2 mol H2 + 1 mol O2 = 44.8 L H2 + 22.4 l O2