A cylinder contains 0.250 mol of an ideal gas. The cylinder has a movable piston on top, which is free to slide up and down, and which keeps the gas pressure constant. The piston's mass is 8,000 g and its circular contact area with the gas is 5.00 cm. 8 kg (a) Find the work (in J) done on the gas as the temperature of the gas is raised from 10.0C to 280C. J (b) What does the sign of your answer to part (a) indicate? The gas does positive work on its surroundings. O The surroundings do positive work on the gas. O There is no work done, by the gas or the surroundings.