Suppose now that the apparatus initially open is now sealed

Question

Assume the absolute zero apparatus is initially open to the air.

The volume of a sphere is: V = 4Πr³/3

a) Assume that air pressure is P_o = 1.00 atm and the air temperature is T_o = 11.9^o C. How many moles of air will the sphere hold?

b) Suppose now that the apparatus, initially open, is now sealed with the air inside. If the apparatus is now heated to to 888^o C, find the pressure inside the apparatus now.

c) Assume now that, while maintaining a temperature of 888^o, the sphere is injected with another 0.0127 moles of air. What is the new pressure inside the ball?