Liquid water becomes a gas at a certain temperature. Which changes will occur in the molecules of water?

Question

a. The molecules will have more potential energy because they will be farther apart.
b. The molecules will have more kinetic energy because they will be moving faster.
c. The molecules will have more potential energy because they will be moving faster.
d. The molecules will have more kinetic energy because they will be farther apart.

Answer 1

When liquid water transitions into a gas (evaporation), the molecules undergo several changes:

1. Increased Kinetic Energy: As water heats up and approaches its boiling point, the molecules gain kinetic energy, which means they move faster. This is due to the increased thermal energy being added to the system.

2. Increased Potential Energy: When water molecules transition from the liquid phase to the gas phase, they move farther apart as they overcome intermolecular forces. This increase in distance between molecules is associated with an increase in potential energy.

Based on this understanding, the correct statements among the options provided are:

a. The molecules will have more potential energy because they will be farther apart.
b. The molecules will have more kinetic energy because they will be moving faster.

Thus, options a and b accurately describe the changes occurring in the water molecules as they transition from liquid to gas. Therefore, both a and b are correct.

Answer 2

select one

Answer 3

If I must select only one option that best describes the changes occurring in the molecules of water as it becomes a gas, I would choose:

b. The molecules will have more kinetic energy because they will be moving faster.

This statement highlights the immediate effect of temperature increase on molecular motion, which is a key characteristic of the gas phase.