Question

Which of the following gases will have the highest velocity at a given temperature? A) Ne B) O2 C) Ar D)N2

Answer 1

Answer: The correct answer is Option A.

Explanation:

Velocity of the gas is inversely related to the molar mass of the given gas. The equation representing the relation between the two is:

$\text{Velocity of the gas}\propto \frac{1}{\sqrt{\text{Molar mass of the gas}}}$

From the above relation, if the molar mass of the gas is more, the velocity of the gas will be less and vice-versa.

The molar masses of the given gases are as:

Ne = 20 g/mol

$O_2$ = 32 g/mol

Ar = 40 g/mol

$N_2$ = 28 g/mol

As, the molar mass of neon is the lowest. Thus, it will have the highest velocity.

Hence, the correct answer is Option A.

Answer 2

The velocity of any gas particles is inversely proportional to the molecular mass of the the gases. Lighter gases posses higher kinetic energy than heavier gases. From the list given, Neon is the lightest of the four gases with an atomic mass of 4.03 thus it is the lightest. Velocity contributes to the  Kinetic energy of the particle. Thus A) Neon is the correct answer.