An unknown gas is placed in a 2.5L vessel at a pressure of 400 mm Hg and a temp of 45C and weighs .834g.
2006-12-22 05:56:19 · 5 answers · asked by janeeyre444 1 in Science & Mathematics ➔ Chemistry
molecular mass comes out to be close to 16.5.
PV = nRT
Use R = 0.08206 (L atm / mol K)
n = 0.834 gm / Molecular weight (that is what you want to know)
T in Kelvin = 318.3
Pressure shouldbe converted to atmosphere from mm 400 mm = 0.5263 atms
and use V in liters = 2.5 L
Solve for MW
(0.834 gm x 0.08206 L atm / mol K x 318.3 K) / (0.5263 atms x 2.5 L)
= 16.55
Good luck
2006-12-22 06:02:54 · answer #1 · answered by pkababa 4 · 0⤊ 0⤋
16 grams
I'll walk you through it so you can do it by yourself next time
first convert mm Hg to atm by dividing by 760 and degrees Celsius to Kelvins by adding 273.
now set up the equation Pressure x Volume = moles x the gas constant (.08206 (l x atm)/(moles x Kelvins)) x temperature.
Solve for moles.
Now divide the given mass by the number of moles
tada 16g/mol.
2006-12-22 14:05:21 · answer #2 · answered by prittykitty22389 2 · 0⤊ 0⤋
It's not oxygen. The molecular weight of oxygen is 32. The gas is either not a pure element (i.e. a mixture) or is not behaving as an ideal gas (i.e. is close to liquifying).
2006-12-22 14:19:02 · answer #3 · answered by Joe 5 · 0⤊ 0⤋
Use the universal gas law equation and solve for moles.
n = PV/RT = 0.05
MM = 0.834g/0.5mol = 16.7grams/mol
2006-12-22 14:14:34 · answer #4 · answered by docrider28 4 · 0⤊ 0⤋
no homework here please.
2006-12-22 14:04:21 · answer #5 · answered by itsbob1 5 · 1⤊ 0⤋