Question

Which change must result in an increase in the average kinetic energy of the molecules of a sample of $N_{2}\left(\right.g\left.\right)$ ?

• A. The pressure changes from 0.5 atmosphere to 1 atm
• B. The volume changes from 1 L to 2 L
• C. The temperature changes from $20^\circ C$ to $30^\circ $ C
• D. The density changes from 2.0 g/L to 2.5 g/L

Answer 1

Answer: (C)

Average K.E. per mol $=\frac{3}{2}RT \propto T$

So, a temperature increases causes the molecules to more faster and this results in a higher average kinetic energy.