Place the substances in order of increasing melting point. CH₄
C₃H₈
C₂H₄

Question

Place the substances in order of increasing melting point. CH₄ C₃H₈ C₂H₄

Quizplus · Accepted Answer

The melting point of a substance generally increases with increasing molecular weight and with increasing intermolecular forces. In the given options, CH₄ has the lowest molecular weight and no significant intermolecular forces, hence it will have the lowest melting point. Among the other two options, C₃H₈ has a higher molecular weight than C₂H₄ and also contains hydrogen bonding, which is an additional intermolecular force. Therefore, it will have a higher melting point. Hence, the correct order of increasing melting point is CH₄ < C₂H₄ < C₃H₈. So, option D is the correct answer.

Place the Substances in Order of Increasing Melting Point