If 1.00 L of an unknown gas at STP has a mass of 5.40 g, what is its molar mass?

1 Answer
May 8, 2016

Answer:

Approx, #121*g*mol^-1#

Explanation:

The molar volume at #"STP"# is #22.4*L*mol^-1#.

Given this, if we divide the mass by the molar quantity of the gas we get an answer in #g*mol^-1# as required:

#(1.00*L)/(22.4*L*mol^-1)# #=# #0.0446*mol#

#"Molar mass"# #=# #(5.40*g)/(0.0446*mol)# #=# #121*g*mol^-1#