Q. The molar mass of the solute sodium hydroxide obtained from the measurement of the osmotic pressure of its aque-ous solution at 27oC is 25 g mol-l. Therefore its ionisation percentage in this solution is
We know that
Molar mass of sodium hydroxide = 40 g/mol
Experimentally determined molar mass = 25 g/mol
Degree of dissociation, alpha = observed value/theoretical value
Percent dissociation = 25/40 * 100 = 62.5%
