Chapter 3, Problem 40A

Interpretation Introduction

Interpretation: Boiling point of $\text{250}\text{ml}$ water and $\text{1000}\text{ml}$ water. Whether the boiling point is an intensive or extensive property.

Concept introduction: A physical property describes the physical changes of a substance. Physical change is a temporary change; it is a reversible change. For example, color, mass, volume, etc. It is divided into two parts: Intensive property and extensive property.

Answer to Problem 40A

The boiling point of $\text{250}\text{ml}$ water and $\text{1000}\text{ml}$ water is the same, which is ${\text{100}}^{\text{°}}\text{C}$ . The boiling point is an intensive property.

Explanation of Solution

Property one that does not depend on the mass of a substance, called intensive property. For example, pressure, density, temperature, etc.

Property one that depends on a substance size or the amount of matter, called extensive property. For example, energy, volume, etc.

According to the question, the composition of water in $\text{250}\text{ml}$ and $\text{1000}\text{ml}$ water is the same, two atoms of hydrogen and one atom of oxygen.

The temp at which the vapor pressure of a liquid equals (similar in quantity) the external pressure or atmospheric pressure is defined as boiling point. The boiling point of water is ${\text{100}}^{\text{°}}\text{C}$ because this is the temp at which the vapor pressure of water is $760\text{ mmHg}$ , or $1\text{atm}$ .

The intensive properties depend on the composition of the substances and the amount cannot affect the intensive property. The intensive property is fixed for the substances. According to this, the boiling point is an intensive property.

Conclusion

The boiling point of water is ${\text{100}}^{\text{°}}\text{C}$ and it is an intensive property.