Chapter 13, Problem 8STP

Interpretation Introduction

Interpretation: It is to be determined whether the statement given is correct or not. If it is correct, then the reason given explains the statement I or not.

Concept introduction:

The temperature at which a liquid's surrounding pressure equals the pressure that the liquid's vapor is exerting is known as the boiling point.

Answer to Problem 8STP

The statement and reason both are correct and the reason explains the given statement.

Explanation of Solution

High altitudes have a lower boiling point for water. When air pressure is lower, it requires less energy to boil water. Thus, water boils below $100°\text{C}$ . Thus, the given statement is correct.

In the air, the number of gas molecules becomes lesser with height, which makes the air less dense than air at sea level. This is what "thin air" means and the thin air applies less pressure.

As boiling point decreases with a decrease in the surrounding’s vapor pressure. So, water boil below $100°\text{C}$ on mountains.

Thus, reason explains the statement.