With standard pressure there is a set list of values. (at STP), most common is 760torr. So whenever you see "at STP" or "at standard temperature pressure" you will use 760torr for pressure. Same thing goes with temperature, if you're not given temp and it says at STP you will use 273K.
For this problem:
You will be using the combined gas law:
(Pressure 1) x (Volume 1) / (Temp. 1) = (Pressure 2) x (Volume 2) / (Temp. 2)
(760torr) x (5.63L) / (287K) = (?) (9.21L) / (287K)
Pressure 2 = 465torr
*Hope this clarifies STP for you! :)
Answer:
I think that you want no, of moles
Explanation:
no, of mole of this amount= 15/44 = 0.341 mole
Oxygen (O) ,Neon (Ne),Argon (Ar)
For one they they sound completely different
