A frictionless piston - cylinder device contains 420 moles of ideal gas at 2 atm and 155 °C. Heat is now transferred to the gas until the temperature reaches 400 °C. If the piston is not attached to a shaft ( Pressure stays constant) and its mass is constant, determine the work (J) done by the gas during this process. Gas constant = 8.21x10-5 (m3.atm/K.mol)

Thermodynamics T-11 All air is removed (vacuumed) from a 2 liter closed container that contains 200 ml of Liquid A and 600 ml of Liquid B at a temperature of 20C. At this temperature Liquid A has a density of 0.825 g/ml and vapor pressure of 25 kPa. Liquid B has a density of 0.750 g/ml and vapor pressure of 15 kPa. What is the mol fraction of vapor from Liquid A in the head space above the liquid surface? A) .25 B) .38 C) .63 D) .75

There is an 500g container made out of aluminum holding 300g of water. The Water and Aluminum have reached thermal equilibrium at 40 degrees Celsius. A 200g block of iron at a temperature of 0 degrees Celsius is later dropped into the water. Using the specific heat for water=4180J/kg/C. The specific heat for aluminum is 900 J/kg/C. The specific heat for iron is 450 J/kg/C. The final temperature of the three materials will be degrees celsius. The thermal energy of the water changes by Joules. (give an amount and include a + if it increases and a - if it decreases) The thermal energy of the aluminum changes by Joules. (give an amount and include a + if it increases and a - if it decreases) The thermal energy of the iron changes by Joules. (give an amount and unit and include a + if it increases and a - if the value decreases)

be sure to follow sign convention.