Question

Comment on the statement:

Equimolal solutions of different non-volatile and non-electrolytic substances dissolved in the same solvent exhibit the same elevation of boiling point.

Answer 1

The statement is correct. Equimolal solutions of different non-volatile and non-electrolytic substances dissolved in the same solvent exhibit the same elevation of boiling point because boiling point elevation is a colligative property.

Colligative properties depend only on the number of solute particles (moles) and not on their chemical nature. Since equimolal solutions have the same molality, they contain the same number of solute particles per kilogram of solvent. Also, as the solutes are non-electrolytic, they do not dissociate into ions, so the van’t Hoff factor (i) = 1 for all.

ΔT_b = K_b . m

Here, K_b​ is constant for the same solvent and mmm is the same for all solutions. Hence, ΔT_b​ will also be the same.