posted by Coug on .
What is the molecular weight of a gas if a 15.0g sample has a pressure of 836 mm Hg at 25.0 degrees C in a 2.00 L flask?
e)none of the above
Please explain... I need to understand how to do this. Thanks.
Use PV = nRT to solve for n.
Then n = grams/molar mass.
I'm still confused... I know that:
R= I think .0821
I have no idea how to change 15.0g to moles, since I do not know what the element is to look at the atomic mass--I know that one mole is avagadro's number, but I'm still really not sure what to do here.