Question

A flask at room temperature contains exactly equal amounts (in moles) of nitrogen and xenon. Sort the conditions based on the gas described. Some may have more than one answer, but noe will have the same answer.
1) Nitrogen has the greater value
2) Xenon has the greater value
3) Both gases have the same value

A. Gas that exerts the greater partial pressure.
B. Gas for which the molecules or atoms have the greatest average velocity
C. Gas that would have a higher rate of effusion through a small hole opened in the flask.
D. Gas for which the molecules or atoms have the greatest average of kinetic energy.

Answer 1

Explanation:

Partial pressure is defined as the pressure that is exerted by one of the gases present in a mixture if it occupies the same volume on its own.

As both nitrogen and xenon have occupied same volume. Therefore, both the gases will have same partial pressure.

It is known that average velocity is inversely proportional to molar mass of a gas. Hence, more is the molar mass of a gas lesser will be its average velocity.

Therefore, xenon having high molar mass will have less average velocity and nitrogen gas will have greatest average velocity.

Also, smaller is the molar mass of a gas more will be its rate of effusion because then its molecules will be able to spread readily into the surrounding.

Hence, nitrogen gas will have a higher rate of effusion through a small hole opened in the flask.

Average kinetic energy is represented as follows.

                 K.E = $\frac{3}{2}kT$

As kinetic energy is directly proportional to temperature. So, with increase in temperature there will occur an increase in kinetic energy of the molecules.

Hence, average of kinetic energy will be same for both the gases.