Suppose you are working with a gas confined in a cylinder with a movable piston which is sealed so that there is no leakage. What would happen if you do the following?

a) Heat the gas at constant pressure

b) reduce the volume while maintaining a constant temperature

c) inject additional gas keeping temperature and volume constant - affect (1) the gas pressure. (2) the amount of matter in moles of gas in the cylinder (3) the average distance between the molecules