Asked by Anon

1. Carbon Dioxide gas has a mass of 86.3 grams. If the molar mass of the sample is 44.2 grams, how many moles of CO2 are present in the sample?

2. That sample of gas is in a 23.2 L container at 12 degrees Celcius. Calculate for the pressure.
Answered by DrBob222
1. mols = grams/molar mass = ?
2. Use PV = nRT
You know V, n, R, T. Remember to convert T to kelvin.

Post your work if you get stuck.
Answered by Anon
V = 23.2 L
T = 285 K
n = ?
R = ?

How do you find the other variables for both questions?
Answered by DrBob222
You calculated mols in # 1. mols = n in the formula PV = nRT
R = a constant of 0.08206 if you want P in atmospheres. If you want R in kPa use 8.314
Answered by DrBob222
From #1, surely you know how to calculate molar mass of a compound. For CO2 it is C = 12; O = 16 x 2 = 32 and 12 + 32 = 44.
Answered by Anon
Thank you. I am still stuck on how to answer #1. The molar mass is 44.2 grams. Since CO2 is 86.3 grams, does that mean that there are two Carbon dioxides present? I'm assuming I double the molar mass here.
Answered by DrBob222
mols = grams/molar mass = ?
mols = 86.3/44.2 = 1.95 mols CO2; however, I don't remember CO2 being 44.2. I don't think CO2 has a molar mass of 44.2
C is 12.01 and O is 32 so I use molar mass CO2 as 44 but I suppose we could plug in 44.01. Then 86.3/44.01 = 1.96 mols CO2
Hope that clears this up.
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