Chapter 23, Problem 48A

Nick suspends a small jar of water in a saucepan, careful that the bottom of the jar doesn’t rest on the bottom of the saucepan. Nick then puts water in the pan, surrounding the jar. He puts the saucepan on a hot stove and is puzzled to see that although the water in the pan comes to a boil, the water in the jar doesn’t. He looks to you for an explanation. Explain.

To determine

To Explain: The reason that the water in the pan comes to a boil but the water in the jar doesn’t.

Answer to Problem 48A

The water in the jar doesn’t boil because the jar is in thermal equilibrium with the surrounding water.

Explanation of Solution

Introduction: The changing phase of water from liquid to gas beneath a liquid surface is termed as the boiling. As the pressure increase on the surface of a liquid, the boiling point of liquid is also increased.

The jar of boiling water having temperature $100°\text{C}$ is in thermal equilibrium with the surrounding water of the saucepan. Therefore, no further heat enters the jar that causes boils. Hence, the water in the jar is not boiling.

Conclusion: Due to thermal equilibrium with the surrounding water, the water in the jar does not boil.