Which of the preceding compounds forms hydrogen bonds with a solvent such as ethanol?
4. CH₃CH₂CH₂NHCH₃ 
5. CH₃CH₂CH₂COOH
6. CH₃CH₂CH₂CH₂F

In each pair, which would you expect to have the higher melting point?

(a)

Which of the preceding compounds forms hydrogen bonds with a solvent such as ethanol?

1. CH₃CH₂OCH₂CH₂OH

2. CH₃CH₂N(CH₃)₂

3. CH₃CH₂CH₂CH₂Br

What is the smallest straight-chain alkane that is a liquid at room temperature (which is about 25 °C)?

Which has

i. the greater density: heptane or octane?

j. the higher boiling point: isopentyl alcohol or isopentylamine?

k. the higher boiling point: hexylamine or dipropylamine?

Explain why

a. H₂O (100 °C) has a higher boiling point than CH₃OH 165 °C2.

b. H₂O (100 °C) has a higher boiling point than NH₃ (-33 °C).

Which has

a. the higher boiling point: 1-bromopentane or 1-bromohexane?

b. the higher boiling point: pentyl chloride or isopentyl chloride?

In Table 7.2, what is the smallest alkane, the smallest terminal alkene, and the smallest terminal alkyne that are liquids at room temperature, which is generally taken to be 20 °C to 25 °C?

N-Methylpyrrolidine has a boiling point of 81 °C, and piperidine has a boiling point of 106 °C.

c. N,N-Dimethylformamide has a boiling point of 150 °C, and N-methylacetamide has a boiling point of 206 °C, for a difference of 56 °C. Explain why these two nitrogen-containing isomers have a much larger boiling point difference than the two amine isomers. Also explain why these two amides have higher boiling points than any of the other four compounds shown (two amines, an ether, and an alcohol).