Colligative

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 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

Consider the following liquids.  Which pairs are miscible?
1. benzene & hexane
2. water & methanol (CH_3OH)
3. water & hexane

• 1, 2 only
• 2 only
• 1 only
• 1, 2, 3

Calculate the mole fraction of ethanol, C_2H_5OH, in a solution that contains 46 g of ethanol & 64 g of methanol CH_3OH.

• 1/3
• 0.42
• 1/2
• 2/3

The vap. pres. of pure water at 85 ^oC is 434 mmHg. What is the vap. pres. of a solution of 100 g of water & 150 g of diglyme, C_6H_14O_3, a nonvolatile substance? 

• 361 mmHg
• 390 mmHg
• 425 mmHg
• 388 mmHg

A 250 mL solution containing 21.4 g of polymer in toluene had an osmotic pressure of 0.055 atm at 27 ^oC. What is the formula weight of the polymer?

• 15,000 g/mol
• 26,000 g/mol
• 32,000 g/mol
• 38,000 g/mol

The boiling point of a solution is ______ the boiling point of the pure solvent.

• higher than
• the same as
• lower than
• higher or lower than

The freezing point of a solution is ____ the freezing point of the pure solvent.

• the same as
• lower than
• higher than
• no relation to

58 grams of NaCl is added to 2 kg of water. What is the molality of the solution?

• 29 m
• 1 m
• 0.50 m
• none of these