1. An air-water vapor mixture at 14.7 psia, 100.°F, and 40.4% relative humidity is contained in a 10.0 ft3 closed tank. The tank is cooled until the water just begins to condense. Determine the temperature at which condensation begins.
2. When the dew point of atmospheric air is between 60.0°F and 70.0°F, the weather is said to be humid, and when it is above 70.0°F it is said to be tropical. If the partial pressure of water vapor in the air is 0.400 psia when the dry bulb temperature is 80.0°F, determine the relative humidity and whether the weather is humid or tropical.