The apparatus illustrated has been assembled. After 20 minutes, a white ring of ammonium chloride appears at position Y. Which statement concerning the molecules of ammonia and hydrogen chloride is correct?
- AMolecules in ammonia have a larger $M_r$ than molecules of hydrogen chloride and so they move more slowly.
- BMolecules in ammonia have a larger $M_r$ than molecules of hydrogen chloride and so they move more quickly.
- CMolecules in ammonia have a smaller $M_r$ than molecules of hydrogen chloride and so they move more slowly.
- DMolecules in ammonia have a smaller $M_r$ than molecules of hydrogen chloride and so they move more quickly.