Two uninsulated, rigid tanks contain air. initially, tank a holds 0.45 kg of air at 800 k and tank b has 0.9 kg of air at 500 k. the initial pressure in each tank is 345 kpa. a valve in the line connecting the two tanks is opened and the contents are allowed to mix. eventually, the contents of the tanks come to equilibrium at the temperature of the surroundings, 289 k. assuming the ideal gas model, determine the amount of energy transfer by heat, in kj, and the final pressure, in kpa.