A hot air balloon of 257m^3 is made from 8.50kg of materials. The outside atmosphere is 1.00 atm, and 18C and pure N2 atmosphere.
CH4 + 2 O2 --> CO2 + 2H2O dHrxn = -890 kJ
All heat from CH4 burning goes into all the air originally in the balloon before heating
SN2 = 0.55 J/gC
What mass in grams of CH4 needed to be burned to achieve neutral buoyancy?