Answer to Question #182045 in General Chemistry for Angela Aguilar Valenzuela

Question

The boiling point of ammonia, NH3, is - 33.4°C and that of sulfur 

dioxide, SO2, is - 10.0°C. Which has the higher vapor pressure at -40°C?

Answer 1

We know that boiling point is the temperature in which the vapour pressure is equal to the atmospheric pressure. Since the boiling point of NH3 is closer to -40°C, it has the higher vapour pressure at this temperature. In order words, many of the ammonia molecules would have turned Gaseous at -40°c compared to sulphur dioxide.