Colligative Properties

What is the freezing point of an antifreeze solution created by adding 651 g of ethylene glycol (CH₂(OH)CH₂(OH)) to 2505 g of water? K_f = 1.86 ^oC/m

• -4.19 ^oC
• 2.2 ^oC
• 0 ^oC
• -7.79 ^oC

What observation(s) reflect(s) colligative properties?
I. A 0.5 m NaBr soln has a higher vapor pressure than 0.5 m BaCl₂ soln.
II. A 0.5 m NaOH soln freezes at a lower T. than pure water.
III. Pure water freezes at a higher T than pure methanol.

• only I
• only II
• only III
• 1 & II

What is the van't Hoff factor for the compound Na₂SO₄

• 1
• 3
• 5
• 7

What is the van't Hoff factor for the compound CH₃OH?

• 1
• 3
• 6
• 9

Calculate the freezing point of a solution made from 72.33 g of propane, C₃H₈, dissolved in 250.0 mL of water.

• -24.81⁰C
• -9.55⁰C
• -6.50⁰C
• -12.20⁰C