A chemist is working with a 4.50 mol sample of an ideal gas. The internal energy of the sample is known to be 14,900 J.

What is the average kinetic energy of each gas molecule? (Remember, Boltzmann’s constant is 1.38 × 10–23 J/K, and the universal gas constant is 8.3145 J/K • mol)

A. 3.66 × 10–21 J
B. 5.49 × 10–21 J
C. 3.08 × 10–19 J

Question

A chemist is working with a 4.50 mol sample of an ideal gas. The internal energy of the sample is known to be 14,900 J.

What is the average kinetic energy of each gas molecule? (Remember, Boltzmann’s constant is 1.38 × 10–23 J/K, and the universal gas constant is 8.3145 J/K • mol)

A. 3.66 × 10–21 J
B. 5.49 × 10–21 J
C. 3.08 × 10–19 J

anonymous · Answer

$$KE_{Average} = \frac{Internal Energy}{Number Of Molecules}$$
Number of Molecules = Number of Moles x Avagadro's Number

anonymous · Answer

I did all of that and got 14969.7355235 which is not an answer choice lol......... @Vandreigan

anonymous · Answer

I'm not sure how you got such a large number.

Avagadro's Number = 6.022 x 10^(23)

You're dividing by this number, so you'll expect a MUCH smaller result than what you have.