Chapter 17, Problem 68A

The phases of matter are solid, liquid, gas, and plasma. What does the addition or subtraction of heat have to do with changes of phase?

To determine

To explain: Effect of addition or subtraction of heat on the four phases of matter.

Answer to Problem 68A

Addition of heat changes phase of matter: solid to liquid, liquid to gas, gas to plasma, and reverse in case of subtraction.

Explanation of Solution

Introduction:

Latent heat is the heat required to change phase of 1 kg substance at the same temperature.

When an amount of heat is applied to a matter phase then its state changes. This heat is known as latent heat. When it is applied to the solid phase, then it changes into the liquid, liquid into gas, gas into plasma. When the same amount of heat is subtracted from it, then also change of phase occurs; plasma into gas, gas into liquid, and liquid into solid.

Conclusion:

Thus, the addition of heat changes phase: solid to liquid, liquid to gas, gas to plasma, and subtraction brings back to the previous state of matter.