Answer to Question #21249 in Inorganic Chemistry for tyler

Question

"What would the mass of air be inside a hot air balloon that has the volume of 5.25 x 10^4 L. The temperature of the air inside is 30 degrees celsius and the pressure is 95.5 kPa. Assume the composition of air is 80% nitrogen gas and 20% oxygen gas to determine the molar mass of air."

Answer 1

For answering this question you need to use the next law:

PV = nRT,where

P-pressure = 95.5 kPa
V- volume = 5,25*10^4 L
R - constant = 8.31
T- temperature = 273+30=303 C

n = PV/RT

n = 95.5*5,25*10^4/ 8.31* 303 = 1991.22mol

"M_w" of air= 0.8*28+0.2*32=28.8

n = m/M_w => m = n*M_w = 1991.22* 28.8 =57.347 kg