posted by Joan .
a balloonist is preparing a trip in a helium balloon. the trip begins in early morning at a temp of 15 degrees Celcius. By mid afternoon, the temp has increased to 30 degrees C. assuming the pressure remains constant at 1.00 atm, for each mole of helium, calculate:
1. the initial and final volume
2. the change in internal energy
3. the work done by helium
4. change in enthalpy