Question

A popular size of scuba-diving tank is 71.2 ft3 because this is the volume that the compressed air inside the tank would occupy at a normal surface pressure of 1 atm. The air in the tank is at a pressure of about 2250 lb/in.2, so the tank itself can have a volume much less than 71.2 ft3. How large does the tank need to be to hold 71.2 ft3? (Hint: Use Boyle's Law: PV = k. Remember that 1 atm = 14.7 lb/in.2.)