Vapor bubbles throughout the liquid as it does when it boils, the vapor has to exert as much pressure as the blanket of air confining it. As a liquid is heated, more of it
turns into vapor, and the vapor pressure increases. When the vapor pressure reaches
atmospheric pressure, the liquid boils. Under greater external pressure, the liquid
boils at a higher temperature.
The graph below shows the vapor pressures of four common liquids as a function of temperature. Refer to the
graph to answer the questions that follow.
1. Which of the substances above
Vapor Pressure of Four Liquids
has
200
the lowest boiling point?
propanone
2. Which of the substances above
ethanol
has
150
washer
a boiling point of 100°C?
3. Which of the substances above
-han
Os
has
Vapor Pressure (kPa)
1013 Pa
the highest boiling point?
4. Which of the substances above
has
the highest vapor pressure at
40°G?