Chapter 14, Problem 80A

Interpretation Introduction

Interpretation: Kelvin temperatures must be used in the calculation that involves gases is to be explained.

Concept introduction: A kelvin is a temperature measurement unit. Since the kelvin scale is based on absolute zero, the coldest measurement possible, there is no negative kelvin temperature.

Answer to Problem 80A

Kelvin temperature is used in gas calculations because a gas's pressure and volume depend on particle kinetic energy. The Kelvin scale is proportional to particle kinetic energy since $0\text{ K}$ (absolute zero) indicates there is no kinetic energy.

Explanation of Solution

The Kelvin scale is proportional to the kinetic energy of particles, as $0\text{ K}$ (absolute zero) denotes the absence of kinetic energy. Since the pressure and volume of a gas depend on its particles' kinetic energy, the Kelvin scale is used in calculations involving gases.

When the absolute temperature of a gas in Kelvin degrees is doubled, so is its kinetic energy. A direct link between temperature and kinetic energy is necessary for calculations based on the gas law. There is no other temperature scale based on absolute zero and temperature.

Conclusion

Kelvin temperature is used in gas calculations because a gas's pressure and volume depend on particle kinetic energy. The Kelvin scale is proportional to particle kinetic energy since $0\text{ K}$ (absolute zero) indicates there is no kinetic energy.