Question

a weather balloon contains 8.80 moles of helium at a ppressure of 0.992 atm and a temperature os 25 C at ground level. What is the volume of the balloon under these conditions?

Answer 1

We can use the ideal gas law equation to find the volume of the balloon.
PV = nRT 
where 
P - pressure - 0.992 atm x 101 325 Pa/atm = 100 514 Pa
V - volume 
n - number of moles - 8.80 mol 
R - universal gas constant  - 8.314 Jmol⁻¹K⁻¹
T - temperature in kelvin - 25 °C + 273 = 298 K
Substituting these values in the equation 
100 514 Pa x V = 8.80 mol x  8.314 Jmol⁻¹K⁻¹ x 298 K
V = 217 L
volume of balloon is 217 L