will give medals- can someone tell me what i'm doing wrong?
"A quantity of gas weighing 7.10g at 741 torr at 44 degrees celsius occupies a volume of 5.40L. What is its molar mass?

V=5.40 L
T=44 degrees C - 317K
p= 741torr = 0.974atm
n=?

I used pv=nrt
(0.974atm)(5.40L)=n(0.08206)(317K)
n=0.2021 moles, but I know that doesn't make sense/incorrect.
I think it is because i solved for the pressure wrong.

Question

will give medals- can someone tell me what i'm doing wrong?
"A quantity of gas weighing 7.10g at 741 torr at 44 degrees celsius occupies a volume of 5.40L. What is its molar mass?

V=5.40 L
T=44 degrees C -> 317K
p= 741torr = 0.974atm
n=?

I used pv=nrt
(0.974atm)(5.40L)=n(0.08206)(317K)
n=0.2021 moles, but I know that doesn't make sense/incorrect. 
I think it is because i solved for the pressure wrong.

coolor · Answer

why do you think that you are wrong tho?

jfraser · Answer

you're asked for the molar mass, but the $n$ in $PV = nRT$ is $moles$, not molar mass. You need to combine that answer with the $mass$ of gas you're also given

x3_drummerchick · Answer

@jfraser the only information they gave me is what is stated above. how should i solve it?

x3_drummerchick · Answer

@coolor its wrong because the answer in thee back of the book was different.

x3_drummerchick · Answer

i figured it out! from what you said about g/mol, i only found the moles. so now i have to divide: n/g  (this is grams per mol=molar mass)
0.2021mol/7.10grams = 35.1g/mol <-- answer :)

jfraser · Answer

you actually have to divide g/n, in order to get grams per mole = molar mass