MECH 3020 Thermodynamics II: Homework set #11, Due 03/11 The solutions are worked out symbolically. 1. Current outside conditions are 19 ◦ C, 43% relative hu-midity. Calculate: (a) The dew point temperature. 6.5 ◦ C (b) The speciﬁc humidity ω . 0.006 (c) The speciﬁc volume of the mixture per kg of dry air . 0.835 2. A 1 m 3 volume of atmospheric air is at 1 atm, 25 ◦ C, and 60% relative humidity. Calculate (a) The partial pressures of the water vapor and the dry air. P v = ϕP sat (25 ◦ C), P a = P-P v (b) The masses of dry air and water. m a = P a V/R a T , m v = P v V/R w T 3. The system in problem 2 is now cooled at constant pres-sure to a temperature of 5 ◦ C. Calculate (a) The volume of the system at the point, during the process, at which water begins to condense into the liquid phase. Find the dewpoint temperature T dp , and V dp = V 1 ( T dp /T 1 ), since total pressure is constant and the gases are ideal. Use Kelvin. (b) The total mass of liquid water that condensed dur-
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