G C When the dishes are all dry, the plates feel cooler to the touch than the plasticwhy? Problems: Hour Exam I, Spring 2007, #8 A balloon filed with 39.1 mol helium has a volume of 876 L at 0.0 oC and 1.00 atm pressure. The temperature of the balloon is increased to 38 oC as it expands to a volume of 998 L, the pressure remaining constant. Calculate E for the helium in the balloon (CHe = 20.8 J/oC mol). Stuck?