Chapter U5.99, Problem 1E

Interpretation Introduction

Interpretation: The reason of not changing temperature of water during boiling needs to be explained.

Concept Introduction: Boiling is the gradual vaporization of a liquid that happens when a liquid is heated, the temperature at which the liquid's vapour pressure is equal to the ambient atmosphere's pressure on the liquid.

Answer to Problem 1E

Boiling needs energy to change liquid into gas. Therefore, the gas molecules which leave the liquid extract thermal energy from the liquid. Hence, temperature remains constant during boiling.

Explanation of Solution

During the boiling process, all of the energy transferred is used to completely break the intermolecular attractions so that molecules can move freely as a gas. As a result, no temperature change is observed during boiling.

Conclusion

Intermolecular forces are the attractive forces that bind the solid or liquid particles tightly. When heat is transferred into a substance, the particles are move faster and temperature increases.