Posted by I on .
The balloon contains 0.30 mol of helium starts at a pressure of 125 kpa and rises to an altitude where the pressure is 55.0 kpa, maintaining a constant 300 {\rm K} temperature.
A)By what factor does its volume increase?
B)How much work does the gas in the balloon do?

physics 
Elena,
p1•V1/T1 = p2•V2/T2á
T1 =T2á
V2/V1=p1/p2=125/55 =2.27þ
W =ν•R•T•ln(V2/V1) = =0.3•8.31•300•ln2.27=614 J.