Chapter 21, Problem 9STP

Interpretation Introduction

Interpretation:

Among the given statements, incorrect statement should be determined which doesn't describe the boiling of liquid process.

1. The temperature of the system rises.
2. Energy is absorbed by the system.
3. The vapor pressure of liquid is equal to atmospheric pressure.
4. The liquid is entering the gas phase.

Concept introduction:

The temperature at which the vapor pressure of a liquid or a substanceis equal to an atmospheric pressure is known as boiling point of a substance or liquid. Each and every substance has its boiling point. The rise of temperature takes place till the boiling point reached, after that temperature remains constant.

Answer to Problem 9STP

Incorrect statementwhich doesn't describe the boiling of liquid process is”The vapor pressure of liquid is equal to atmospheric pressure”. Thus, option (C) is correct.

Explanation of Solution

(A)

The boiling of a liquid results in the phase change that is a liquid phase changes into gaseous phase. Increase in temperature at a certain point causes a liquid to boil. Every liquid boils at its boiling point and when boiling point reached, temperature stop rising. Liquid boils when it gains or absorbs enough heat.

Thus, the statement “The temperature of the system rises” describes the boiling of liquid process.

(B)

The boiling of a liquid results in the phase change that is a liquid phase changes into gaseous phase. Every liquid boils at its boiling point and when boiling point reached, temperature stop rising. The boiling of liquid needs energy in the form of heat. When a liquid boils, heat will increases or a liquid absorbs energy until boiling takes place.

Thus, the statement “Energy is absorbed by the system” describes the boiling of liquid process.

(C)

The boiling of a liquid results in the phase change that is a liquid phase changes into gaseous phase. During boiling of liquid, the vapor pressure increases higher than the atmospheric pressure. The vapor pressure and atmospheric is not equal to each other when a liquid boils.

Thus, the statement “The vapor pressure of liquid is equal to atmospheric pressure” doesn’t describes the boiling of liquid process.

(D)

The boiling of a liquid results in the phase change that is a liquid phase changes into gaseous phase.

Thus, the statement “The liquid is entering the gas phase” describes the boiling of liquid process.