1)why is the boiling point of solution higher than that of pure solvent? 2)Why vapour pressure of solution is less than that of solvent. Explain and give reasons

Most solutions have a HIGHER boiling point than the pure solvent. The solution has a higher Bp because all solutions have lots of ionic attraction between the different ions in the solution. This ionic attraction makes the solution less volatile (i.e. less likely to evaporate). So, higher boiling point.

 

Low vapor pressure and high boiling point mean almost the same thing - the solution wants to resist evaporating because there is ionic attraction between the atoms.