What does 100 cubic feet of air weigh at sea level, at both 70 and 80 degess f. ? sorry, I'm bad with numbers. Thanks for your help!
2006-11-23 04:35:41 · 6 answers · asked by metermike 2 in Science & Mathematics ➔ Mathematics
PV=nRT
n=PV/RT
R=10.7316 ft³ · psi · °R-1 · lbmol-1
P=14.7 psi
T=530 R, 540 R
V=100ft^3
@70F=530R
n=14.7*100/(10.7316*530)=.2585
mol wt=28.8
m=28.8*.2584=7.44 lb
@ 80f=540R
n=14.7*100/(10.7316*540)=.2537
m=.2537*28.8=7.31 lb
2006-11-23 05:08:17 · answer #1 · answered by yupchagee 7 · 16⤊ 0⤋
Air consists of approx. 79%N2 and 21%O2.
Mol. wt = O.79 x 28 + 0.21 x 32 = 28.84 g/ mol
Therefore, mass per liter = 28.84/ 22.40 = 1.288 g at STP
(Note that in the answer I have only recorded 3 decimal points, ie 1 mg. Greater accuracy is unnecessary and confusing)
2006-11-23 06:42:18 · answer #2 · answered by Anonymous · 0⤊ 0⤋
70 degrees F, 100 ft3 = 7.50 lbs approx
80 degrees F, 100 ft3 = 7.35 lbs approx
2006-11-23 06:29:37 · answer #3 · answered by Anonymous · 0⤊ 0⤋
I think air ways Gravity
2006-11-23 05:03:18 · answer #4 · answered by Anonymous · 0⤊ 1⤋
You should be able to calculate it pretty easy with the density values from this website:
http://www.engineeringtoolbox.com/air-desity-specific-weight-d_600.html
2006-11-23 04:45:30 · answer #5 · answered by Jim Burnell 6 · 0⤊ 0⤋
Air doesn't have any weight
2006-11-23 05:18:55 · answer #6 · answered by ATS 2 · 0⤊ 1⤋