Question

Calculate the molar mass AND identify the gas if 3.25 kg of this gas is stored in a 15.00 L tank and exerts a pressure of 120.0 atm at a constant temperature of 66.0°C

Answer 1

PV = nRT

sticking with L, atm, mol, K as our units

P = 120.0 atm
V = 15.00 L
n = moles (you'll solve for this)
R = 0.0821 L*atm/mol·K
T = 66 + 273.15 (to convert to K)

plug in and solve for n

once you have n, you can set n = moles = mass/molar mass
let mass = 3.25kg * 1000 (to convert to grams) and solve for molar mass

Answer 2

Oh, one more thing, it also asks to identify the gas - simply look at the periodic table to see what matches your MM

Answer 3

i solved for n already and i got 64.71 mols

Answer 4

yh i got 50.22g/mol and i checked the periodic table , there is no element like that

Answer 5

Hm. could be diatomic? I'll check what I can find.

Answer 6

Having some hard time finding something close

Closest I can find is chloromethane? I'm pretty sure we did the calculations correctly, not sure what they're looking for.

Answer 7

Unfortunately we don't have a lot of chem people but perhaps @AZ could take a look at this if he gets online later today

Answer 8

You solved it correctly. It probably is chloromethane unless answer choices are provided and there's something else with a molar mass closer to 50.27

Answer 9

yh thanks i got it i think it is closr to vanadium

Answer 10

Chloromethane is closer and is also a gas.

Vanadium is an element and is a metal that's rarely found in nature