Question

A sample of an unknown gas effuses in 12.1 min. an equal volume of h2 in the same apparatus under the same conditions effuses in 2.42 min. what is the molar mass of the unknown gas?

Answer 1

According to Graham's Law of effusion, the rate of effusion of a gas is inversely proportional to the square root of its molar mass. By comparing the rates of effusion of H2 gas and the unknown gas, we can calculate the molar mass of the unknown gas. The molar mass of the unknown gas is approximately 0.404 g/mol.

Step-by-step explanation:

Graham's Law of effusion states that the rate of effusion of a gas is inversely proportional to the square root of its molar mass.

Let's use the given information to calculate the molar mass of the unknown gas.

According to the question, an equal volume of H2 effuses in 2.42 min, while the unknown gas effuses in 12.1 min.

Applying Graham's Law, we can set up the following ratio:

(Rate of H2 effusion) / (Rate of unknown gas effusion) = √(Molar mass of unknown gas) / √(Molar mass of H2)

Substituting the given values, we have:

2.42 / 12.1 = √(Molar mass of unknown gas) / √(2.02 g/mol)

Simplifying this equation, we find:

Molar mass of unknown gas = (2.42 / 12.1) * (2.02 g/mol)

Calculating this, we get:

Answer 2

MW H2 = 2

MW 2 = ?

rate 1 = 1/12.1

rate 2 = 2.42

aopply graham law

Rate1/rate2 = sqrt(MW2/MW1)

(12.1/2.42)^2 = MW2/2

MW = 2(12.1/2.42)^2 = 50 g/mol

Therefore, the molar mass of the unknown gas is 50 g/mol