Colligative Properties

Question 1

What are colligative properties?

Answer 1

Solution properties that depend on the number of solute particles rather than the solute’s identity

Question 2

What is vapor pressure lowering (ΔP)?

Answer 2

A solution has lower vapor pressure than a pure solvent

Question 3

What formula do you use to find the difference in vapor pressure between a solution and pure solvent using Raoult’s Law?

Answer 3

ΔP = Xsolute * P^0 solvent
X = mole fraction

Question 4

What is boiling point elevation (ΔTb)?

Answer 4

A solution has a higher boiling point than a pure solvent

Question 5

What is freezing point depression (ΔTf)?

Answer 5

A solution has a lower freezing point than a pure solvent

Question 6

What formula do you use to find ΔTb from molality?

Answer 6

ΔTb = (Kb)m

Question 7

What formula do you use to find ΔTf from molality?

Answer 7

ΔTf = (Kf)m

Question 8

What formula do you use to find the freezing point of a solution from ΔTf?

Answer 8

Tf (soln) = Tf (solvent) - ΔTf

Question 9

What formula do you use to find the boiling point of a solution from ΔTb?

Answer 9

Tb (soln) = Tb (solvent) + ΔTb

Question 10

What is the van’t Hoff factor (i)?

Answer 10

(moles of particles in a soln)/(moles dissolved in solute)

Question 11

What is the formula for ΔP for strong electrolytes?

Answer 11

i(X solute * P^0 solvent)

Question 12

What is the formula for ΔTb for strong electrolytes?

Answer 12

i(Kb m)

Question 13

What is the formula for ΔTf for strong electrolyes?

Answer 13

i(Kf m)