a 5.00 liter sample of gas measured at 27.0 Celsius & 1.25 atm of pressure has a mass of 10.13 g. What is the molecular weight of gas in u?
a. 2.50 x 10 ^-2
b. 0.898
c. 39.9
d. 2.57
2007-11-19 05:06:17 · 3 answers · asked by Katrina Green 2 in Science & Mathematics ➔ Chemistry
T = 27 + 273 = 300 K
pV = nRT
n = pV / RT = 1.25 x 5.00 / 0.0821 x 300 = 0.254
MM = 10.13 g / 0.254 =39.9 u
2007-11-19 05:15:26 · answer #1 · answered by Dr.A 7 · 1⤊ 0⤋
PV = nRT = (g/mw)RT (mw=molecular weight)
mw = gRT/PV
mw = (10.13g)(0.082L-atm/mol-K)(300K)/(1.25atm)(5.00L) = 39.9g (c.)
2007-11-19 13:18:50 · answer #2 · answered by steve_geo1 7 · 0⤊ 0⤋
use pV=nRT
n=6.25/24.629...
n=0.25376...
MW = m/n
MW = 10.13g/0.25376mol
MW = 39.9
I think this is it.
2007-11-19 13:19:38 · answer #3 · answered by Help! 1 · 0⤊ 0⤋