A Partially weather balloon has a volume of 195 L at a pressure of 0.993 atm. What will be the pressure in the balloon when it is inflated to a volume of 7500 L? (assume to temp. change)

Answer 1

p1v1 = p2v2

Answer 2

Use Boyles Law if mass of gas and temperature are unchanged. (P1)(V1) = (P2)(V2). However, you must give temperature change if that is to be taken into account. On the average, temperature of the atmosphere drops 2-deg Celcius per 1000-ft of elevation. Just using the data given and Boyles Law, the atmospheric pressure would have decreased to 0.026 atm in order for balloon to increase volume to 7500L. Base on standard pressure lapse rate at ~0.001 atm/1000 ft => Altitude of balloon ~ 30,000 ft. A std temp laps rate of 2-deg Celcius / 1000 ft => Temp ~ -60-deg Celcius from surface temp. Assuming surface temp is ~25-deg Celcius to a Temp of -60-deg celcius, the pressure would drop to ~0.019-atm at 30,000ft where temps are ~-60-deg Celcius.