Solutions

Question 1

What are solutions?

Answer 1

One or more substances (solutes) mixed at the molecular level (dissolved) in a medium (solvent)

Solutions can be gas mixtures or even solids

Question 2

What is the formula for Molarity A?

Answer 2

moles of solute of A/ volume of solution (L)

Question 3

What is mole fraction of XA?

Answer 3

moles of solute of A / moles of solution

Question 4

How do you calculate percent A by mass?

Answer 4

mass of solute A / mass of soln * 100

Question 5

For substances to form a solution what interactions must be overcome?

Answer 5

both solute-solute and solvent-solvent

Question 6

What are colligative properties?

Answer 6

Solution properties that depend on concent’n of solute, not its identity

Ex: freezing point depression: solutes lower freeezing point of the solvent

Boiling point elevation: solutes raise boiling point of the solvent

Vapour pressure lowering: solutes decrease vapour pressure of the solvent

osmotic pressure: Pressure that must be applied to a solution to prevent osmosis from a sample of pure solvent.

Question 7

What do non-volatile solutes decrease?

Answer 7

The vapour pressure of the solvent.

Question 8

What do non-volatile solutes contribute to?

Answer 8

Both solute and solvent contribute to vapour pressure

Question 9

What is oosmotic pressure?

Answer 9

Pressure that must be applied to the solution to prevent osmosis from a sample of pure solvent.