Chapter 13, Problem 62A

Interpretation Introduction

Interpretation: It is to be explained that atmospheric pressure is much lower on the top of mountains than at sea level

Concept introduction:

The pressure that vapor molecules apply to a solid or liquid surface in an equilibrium state is referred to as the surface's vapor pressure.

Answer to Problem 62A

The density of air decreases with height.

Explanation of Solution

Since there are fewer gas molecules in the air at higher altitudes, it is less dense than the air nearer to sea level. Less no. of molecules in gas means lower vapor pressure. When compared to air at a lower altitude, thin air exerts less pressure.

That is why vapor pressure in mountains is less than the sea level.