Question

Why is molar mass inversely proportional to the colligative property?

Answer 1

Because they are all dependent on the number of particles present in the solution i.e. the number of moles of solute.

Property proportional to moles

Therefore property proportional to mass/molar mass

Therefore property proportional to 1/molar mass.

Answer 2

When we a non-volatile solute in a volatile solvent we observe that there is a decrease in vapour pressure of the solution. This decrease of vapour pressure can be quantitatively used to measure several properties of liquid solutions.These properties depend more on solute particles of the solution and are called colligative properties. The word “colligative” is derived from the Latin word “coligare” which means “to bind together”.