Question

if the statement is true, write true in the blank. if it is false, italicized word(s) with the word(s) that will make the statement

1. colligative properties depend primarily on the mass of the solution.
2. if a large concentration of salt were added to pure water in a covered beaker, the vapor pressure of the water would be expected to decrease.
3. as the temperature of a given liquid is increased, its vapor pressure decreases.
4. the boiling point of a solution containing a nonvolatile solute is higher than the boiling point of the pure solvent.
5. the freezing point of a solution containing a nonvolatile solute is higher than the freezing point of the pure solvent.
6. when calculating a solutes effect on boiling and freezing points, concentration should be measured as molality.

Explanation:

1. Colligative properties depend on the number of solute particles, not the mass of the solution.
2. Adding a solute (salt) to a solvent (water) lowers the vapor pressure of the solvent.
3. As temperature increases, the vapor pressure of a liquid increases because more molecules have enough energy to escape into the gas phase.
4. A non - volatile solute raises the boiling point of a solution compared to the pure solvent. This is due to the lowering of vapor pressure by the solute.
5. A non - volatile solute lowers the freezing point of a solution compared to the pure solvent.
6. Molality (moles of solute per kilogram of solvent) is used when calculating boiling and freezing point changes because it is temperature - independent (unlike molarity).

Answer:

1. false, number of solute particles
2. true
3. false, increases
4. true
5. false, lower
6. true