Question

An effusion container is filled with 2 L of an unknown gas. It takes 350 s for the gas to effuse into a vacuum. From the same container under the same conditions--same temperature and initial pressure, it takes 229 s for 2.00 L of O2 gas to effuse. Calculate the molar mass (in grams/mol) of the unknown gas.

Answer 1

6.85g/mol

Step-by-step explanation:

According to the Graham's law of diffusion,the rate of diffusion is inversely proportional to the square root of molecular mass.

k=r√m.m

k=constant

r=rate of diffusion or effusion

m.m=molecular mass

taking ''1'' and '2" to be the two gases 1=oxygen,2=unknown gas

r1√m1=r2√m2,molar mass of oxygen=16

mathematically√m2=229√16/350

√m2=2.617

m2=6.85g/mol