Background: Continued heating of the water after the ice has completely melted will now increase the kinetic energy of the liquid molecules and the temperature will rise. Assuming that the atmospheric pressure is standard, the temperature will rise steadily until it reaches 100°C. At this point, the added energy from the heat will cause the liquid to begin to vaporize. As with the previous state change, the temperature will remain at 100°C while the water molecules are going from the liquid to the gas or vapor state. Once all the liquid has completely boiled away, continued heating of the steam (remember the container is closed) will increase its temperature above 100°C.

Situation: Ann wanted to make broth so she but some frozen stock and a little water in a pot on the stove to simmer. A few minutes later the phone rang. She started talking to her friend and forgot the broth was on the stove. When she returned to the kitchen the stock had melted and the broth had boiled away.

Question: Did the kinetic energy increase or decrease as the temerature rose?

Situation: Ann wanted to make broth so she but some frozen stock and a little water in a pot on the stove to simmer. A few minutes later the phone rang. She started talking to her friend and forgot the broth was on the stove. When she returned to the kitchen the stock had melted and the broth had boiled away.

Question: Did the kinetic energy increase before or after the frozen stock melted?

Situation: Ann wanted to make broth so she but some frozen stock and a little water in a pot on the stove to simmer. A few minutes later the phone rang. She started talking to her friend and forgot the broth was on the stove. When she returned to the kitchen the stock had melted and the broth had boiled away.

Question: did the temerature rise before or after the stock melted?

Situation: Ann wanted to make broth so she but some frozen stock and a little water in a pot on the stove to simmer. A few minutes later the phone rang. She started talking to her friend and forgot the broth was on the stove. When she returned to the kitchen the stock had melted and the broth had boiled away.

Question: What happened to the broth when it reached 100 degrees C?

Situation: Ann wanted to make broth so she but some frozen stock and a little water in a pot on the stove to simmer. A few minutes later the phone rang. She started talking to her friend and forgot the broth was on the stove. When she returned to the kitchen the stock had melted and the broth had boiled away.

Question: Did the temerature rise or stay the same as it boiled?

Situation: Ann wanted to make broth so she but some frozen stock and a little water in a pot on the stove to simmer. A few minutes later the phone rang. She started talking to her friend and forgot the broth was on the stove. When she returned to the kitchen the stock had melted and the broth had boiled away.

Question: Was the temerature stable or rising as it melted?

Situation: Ann wanted to make broth so she but some frozen stock and a little water in a pot on the stove to simmer. A few minutes later the phone rang. She started talking to her friend and forgot the broth was on the stove. When she returned to the kitchen the stock had melted and the broth had boiled away.

Question: Did the temperature rise steadily or unevenly after melting?