Question

The molar mass of a certain gas is 58.1 g/mol. What is the density of the gas in g/L at STP?

Answer 1

use the ideal gas law,

PV=nRT -> P=nRT/V

sub in: n=m/M

P=mRT/MV

sub in: d=m/V

P=dRT/M

rearrange..

d=PM/RT

Answer 2

where little m is mass in grams and big M is molar mass.