Could somebody help me with a Chemistry question?

Question

Could somebody help me develop a hypothesis on how the boiling point of a solution compares to that of pure solvent?

Answer 1

this has already been done.

A solution/mixture has a higher boiling point than the pure solvent.

It's a colligative property known as boiling point elevation. The boiling point of a solution (a solute dissolved in a solvent) will be higher than that of a pure solvent alone.

Delta T = Kb x m x i

Where Kb is the boiling point constant for a particular solvent, m is the concentration (molality of the solution) and i is the vant Hoff factor.

Answer 2

Qualitatively, if you add solute, the boiling point goes up. That could be shown by just two experiments - pure solvent and a solution.

Quantitatively, you should develop the hypothesis that the boiling point of the solvent rises by a fixed amount for a fixed quantity of solute being added to the pure solvent. A series of experiments measuring the boiling points of a succession of increasingly concentrated solutions should do the trick.

Answer 3

BP's of pure solvents are elevated by the addition of solutes or aditional solvents. epressed being that the T is lowered, typically. I can't remember the exceptions..

Take Water. Boiling Pt= 100 C. Add some salt to the water, or sugar... or another solvent, say gasoline... the water will boil after it gets to 100 C.

So that would be your Hypothesis- that the BP is affected in some way as the discreetness of the original substance is compromised.

Answer 4

The boiling point of either is the temperature at which its vapor pressure equals that of the atmosphere. In a pure solvent, if you could "see" the molecules, you would "see" that the surface is covered with solvent molecules. In a solution of a nonvolatile solute like sugar, you "see" that there are several sugar molecules coveruing the surface along with a lot of solvent ones. You must heat the solution to a higher temperature to boil it, because the solvent molecules have less of a chance to get away, blocked as they are by solute molecules.