If a sample of gas which weighs 0.400 g has a volume of 250 mL at STP, what is the molecular weight of the gas?

1 Answer
Jun 4, 2016

Answer:

Approx. #36.0*g*mol^-1#

Explanation:

The molar volume of an Ideal Gas at #STP# is #22.4*L*mol^-1#.

We assume that the gas behaves ideally, and thus we multiply the given density #(g*L^-1)# by the molar volume at #STP#, to give....

#(0.400*g)/(0.250*cancelL)xx22.4*cancelL*mol^-1# #=# #35.9*g*mol^-1#.

Given this molecular weight, the gas is quite possiby #HCl#.