Question

ck - 12 exploration series
phase change
heat and changes of state
exploration questions
challenge me questions 1 - 5: as you explore the simulation, answer the following questions.

1. does the temperature of the water rise while it is boiling?
2. what is the relationship between molecular motion and energy?
3. when you boil water, why does the level of liquid decrease?
4. label each arrow using the following words: melting, freezing, sublimation, deposition, condensation, and evaporation.

gas
liquid ↔ solid

1. can pure water exist as a liquid at 110°c? why or why not?

Explanation:

1. During boiling, water is in a phase - change process from liquid to gas at its boiling point (100°C at standard atmospheric pressure). The heat energy is used for the phase - change rather than increasing the temperature, so the answer is no.
2. The more energy molecules have, the more vigorously they move. Kinetic energy of molecules is related to their motion. Higher energy means higher - speed and more random motion.
3. When water boils, it changes from the liquid phase to the gas phase (water vapor). The water vapor escapes into the atmosphere, so the level of the liquid water decreases.
4. Gas to Liquid: condensation; Liquid to Gas: evaporation; Liquid to Solid: freezing; Solid to Liquid: melting; Solid to Gas: sublimation; Gas to Solid: deposition.
5. At standard atmospheric pressure (1 atm), pure water boils at 100°C and turns into a gas. But at higher pressures, the boiling point of water increases. So, at pressures above 1 atm, pure water can exist as a liquid at 110°C.

Answer:

1. No
2. More energy leads to more vigorous molecular motion.
3. Because water changes to water vapor and escapes.
4. Gas to Liquid: condensation; Liquid to Gas: evaporation; Liquid to Solid: freezing; Solid to Liquid: melting; Solid to Gas: sublimation; Gas to Solid: deposition
5. At standard pressure, no. But at higher pressures, yes.