Consider equal masses of O₂(g) and HI(g) that are in separate containers with equal volume and temperature. Which of the statements below is true?

• A. The average kinetic energy of the HI molecules is greater than that of O₂ molecules.
• B. The average velocity of the HI molecules is greater than that of the O₂ molecules.
• C. The pressure in the HI container is less than that in the O₂ container.
• D. Both gases will have equal pressures.
• E. There are fewer O₂ molecules than HI molecules.

Answer: (C)