Chapter 14, Problem 17A

Interpretation Introduction

Interpretation: The microscopic process that takes place on boiling a liquid has to be given.

Concept introduction: The process by which liquid changes into vapor on heating to its boiling point is called as boiling. Boiling occurs when atoms (or) molecules of a liquid have the capacity to spread out sufficiently to change from a liquid to gaseous, resulting in the formation of bubbles. The bubbles in a boiling liquid consist of molecules of liquid that has gained sufficient energy to change to the gaseous state.

Answer to Problem 17A

The formation of bubbles takes place when the liquid reaches the boiling point. These bubbles come to the surface releasing water vapor. This happens because as heat is added, the molecules vibrate vigorously until they have sufficient energy to escape.

Explanation of Solution

When the process of boiling occurs, the more energetic molecules turns to a gas, spread out and forms bubbles. The bubble rises to the surface and enters the atmosphere. It needs energy to change from a liquid to a gas.

The formation of bubbles takes place when the liquid reaches the boiling point. These bubbles come to the surface releasing water vapor. This happens because as heat is added, the molecules vibrate vigorously until they have sufficient energy to escape.

Conclusion

Bubbles are formed when liquid reaches the boiling point. The bubbles rise to surface and releases water vapor. This happens because when heat is added, the molecules vibrate more and more until they have sufficient energy to escape.