Answer to Question #24493 in Physical Chemistry for MAHADEVAN

Question

two solutions of sodium chloride and glucose in water, both has 0.1molal strength, which one has a higher boiling point? why?

Answer 1

In the same volume of water, one mole of NaCl will give rise to a greater boiling point elevation. This is explained by the fact that boiling point elevation is a colligative property, that is, the relative amounts of the constituents are important and not their identity. We can determine by inspection that, upon dissociation, more ions will be produced by NaCl than glucose since there are more component parts in the NaCl molecule.So, for one mole of NaCl, we will produce one mole of Na+ and one mole of Cl- (two total),so for one mole of glucose it is one mole of component part,because it is not dissociated compound. By employing the principle stated above, we can come to the correct conclusion.