Humid air is enclosed in a 4.00-liter flask at 40.0 C. The flask is slowly cooled. When the temperature reaches 20.0C, drops of moisture become visible on the flask wall. Although the pressure in the flask changes when the temperature drops, it remains close enough to 1 atm for the psychrometric chart to provide a close representation of the behavior of the system throughout the process. Use the chart to solve the following problems. See Example 8.4-5. Reference Materials Physical Property Tables Psychrometric chart - Sl units Reference sates: H20 (liquid, 0C, 1 atm) dry air (0C, 1 atm). (Data obtained from Carrier Corporation.) Psychrometric chart- U.S. customary units Reference sates: H20 (liquid, 32F, 1 atm) dry air (OF, 1 atm). (Data obtained from Carrier Corporation.) Humid Air Properties Correct. What were the relative humidity, absolute humidity, and wet-bulb temperature of the air at 40.0 C? Relative humidity: 33 % Absolute humidity: 0.0147 kg H20/kg Dry Air Wet-bulb temperature: 25.42 C Mass Your Answer Correct Answer Correct. Calculate the mass of dry air in the flask. 4.67 g Calculate the mass of water in the flask. 0.065 g Hint Solution Attempts: 3 of 3 used Enthalpy Change Correct. Calculate the enthalpy change in joules undergone by the air in going from 40.0 C to 20.0C.-92.21 J (enter correct sign) Closed System Energy Change Check the units on R. Write an energy balance for this closed-system process, taking the wet air in the flask as the system, and use it to calculate the heat in joules that must be transferred from the wet air to accomplish the cooling. i ! A (Assume ideal gas behavior, so that H = U + RT.) =