Question

Define boiling point elevation. Boil about 100 ml of water and add about 10 to 15 gm of salt ( NaCl ) to this. Write your observations and conclusions. *

Answer 1

Observation:

Elevation of boiling point is nothing but, when a non volatile solute is added to volatile solvent, it's vapour pressure decreases, and hence, temperature needed to boil the solution will be more than that of temperature needed to boil the pure solvent.

when you boil 100ml of pure water, it's boiling point is 100°C, but when you boil 100ml water with 10g to 15g of NaCl it's boiling point will increases, means you need little more temperature to boil this solution because of lowering of vapour pressure of the solution.

Conclusion:

Boiling point of solution is depend on the amount of Solute particles and it is irrespective of nature of the Solute, the more the number of Solute, more will be the boiling point of solution and it is called as Colligative Property.