Question Detail

CHM 102 Practice Questions Objective Question

Question

As the molecular weight of alkanes increases, how do the boiling point and melting point change?
Options
A boiling point increases ; melting point increases.
B boiling point increases ; melting point increases.
C boiling point increases ; melting point decreases
D boiling point increases ; melting point increases sequentially for alkanes over four carbons.
Correct Answer
Correct Answer

Option D is the correct answer.

Detailed Explanation

As molecular weight increases, boiling points increase steadily. Melting points also generally increase but not as smoothly; there is a zigzag pattern due to packing efficiency in the solid state, especially for alkanes with more than four carbons.

Hint

How do boiling points and melting points vary with molecular weight?

Question Info