13.2 The nature of liquids

What factors help determine the physical properties of liquids?

• The motion and intermolecular forces between their particles.

• The temperature.

• The temperature and the pressure.

• The temperature, pressure, volume and their intermolecular forces.

In terms of kinetic energy, explain how a molecule in a liquid evaporates.

• A liquid molecule vaporizes first by obtaining kinetic energy then evaporates.

• A liquid molecule will evaporate only when the liquid molecules have obtained a minimum amount of kinetic energy to break free.

• Only a gas can evaporate.

• Gases can evaporate and vaporize.

A liquid in a closed container has a constant pressure. What is the relationship between the rate of evaporation of t he liquid and the rate of condensation of the vapor in the liquid.

• All the liquid evaporates, then some condenses.

• All the liquid condenses, then some evaporate.

• Some liquid evaporate, some liquid condenses.

• None of the above.

What condition must exist for a liquid to boil?

• If left untouched, the liquid will begin to boil by itself.

• A liquid must have the highest kinetic energy possible for it to begin boiling.

• The liquid must gain and then lose kinetic energy to boil

• The liquid must have enough kinetic energy to boil.

Which of the following reasons explain why the boiling point of a liquid varies with atmospheric pressure?

• Atmospheric pressure and boiling point are directly related. If the pressure increases, then the boiling point will increase.

• Boiling point is not affected that much by atmospheric pressre.

• Atmospheric pressure and boiling point are inversely related. If the pressure increases, then the boiling point will decrease.

• Boiling points can only be measure at sea level.

Determine which of the following reasons explain how evaporation lowers the temperature of a liquid.

• When a liquid evaporates, it means that molecules have enough kinetic energy to begin turning into a vapor.

• When a liquid evaporates, it means that molecules have enough kinetic energy to begin turning into a vapor and all the molecules with the highest kinetic energy leave, leaving only the colder molecules.

• When a liquid evaporates, it means that molecules have enough kinetic energy to begin turning into a vapor and all the molecules with the lowest kinetic energy leave, leaving only the hotter molecules.

• A liquid begins to vaporize only after molecules have obtained the highest kinetic energy possible, then evaporate. When the molecules evaporate, the molecules with the highest kinetic energy stay and the ones with the lowest kinetic energy leave.