What happens to the osmotic pressure of a solution when a different solute is added?
Decreases
First decreases, then increases
Increases
None
What is the osmotic pressure of a 0.01 M solution of NaCl at 305 K?
190 mmHg
380 mmHg
0.25 atm
25 kPa
What is the molar mass of a nonelectrolyte solute that causes an osmotic pressure of 15 torr at 25 oC when 0.1 g of the unknown are dissolved in water to form a total volume of 125 mL?
991 g / mol
91 g / mol
2500 g / mol
None of the above
A careless experimenter placed a permeable membrane that allows the flow of both solute and solvent molecules through the membrane in the osmotic pressure measuring setup? Which of the following would be the result of his experiment?
The solution level would be higher than the solvent level.
The solvent level would be higher than the solution level.
The two levels would remain the same because both solute and solvent can flow through the membrane.
Which of the following best explains a lower than expected boiling point?
Vapor pressure lowering
Freezing point depression
The use of a volatile solute.
Which of the following would explain a higher than expected boiling point elevation?
The thermometer is incorrect.
The solute is an electrolyte.
The solution is a nonelectrolyte.
The solution is very viscous.
What is the boiling point of a 1.2 m aqueous solution of a nonelectrolyte? The Kb of water is 0.51 oC kg / mol.
100.6 degrees C
99.4 degress C
0.612 degrees C
Which colligative property predicts the boiling point elevation phenomenon?
Osmotic pressure
Viscosity elevation
Which of the following is not true about freezing points?
They are a property only of the pure solvent and, therefore, cannot be changed.
They can be increased by the addition of a non-volatile solute.
They can be decreased by the addition of a non-volatile solute.
The can be increased by the addition of a volatile solute.
How can we rationalize a situation where the vapor pressure of a solution is greater than that of the pure solvent despite Raoult's law that predicts a lower vapor pressure?
We forgot to include Herny's law in our analysis.
Entropy dictates that there is a random chance of violating any law.
Experimental error
Raoult's law is only valid for nonvolatile solutes, the solute must be a volatile one.
