Question

Hi there - My labs and lectures aren't in synch at the moment so we are now doing a prelab that is asking for info I haven't been taught yet uggg...

The prelab question I'm having trouble with is as follows:

What is the volume at STP for 0.415 g of argon gas? Also, what is the density of argon at STP?

my answer is probably completely wrong because I had no idea how to correctly work this out, but I did

molar volume of STP = volume of Argon/# of mol of Argon =0.415g/39.95mol = 0.01g/mol

Please when answering this question go step by step so I understand this completely.

Thanks...

Answer 1

0.415 g Ar = how many moles.
0.415/molar mass Ar = ??
Then 1 mole occupies 22.4L so ? moles will occupy .....L. You have calculated moles; convert that to volume at the rate of 22.4L for 1 mole.

Density of Ar = mass/volume and you can get that at STP 39.95/22.4 = ?g/L.