The correct answer is option 3. C < A < B < D.
Let us look into the details of why the order of increasing boiling points is \( C < A < B < D \) and why option (3) is correct.
1. \(C_2H_5N(CH_3)_2\) - Dimethylpropylamine (C):
Dimethylpropylamine is a tertiary amine and tertiary amines generally have weaker intermolecular forces compared to primary and secondary amines. It lacks hydrogen bonding, and its molecular weight is relatively lower than the other compounds. We expect it to have the lowest boiling point among the given compounds.
2. \((C_2H_5)_2NH\) - Diethylamine (A):
Diethylamine is a secondary amine. While it does not have hydrogen bonding, it can exhibit dipole-dipole interactions. It has a higher molecular weight compared to dimethylpropylamine. The presence of dipole-dipole interactions and a higher molecular weight makes it likely to have a higher boiling point than dimethylpropylamine.
3. \(n-C_4H_9NH_2\) - Butylamine (B):
Butylamine is a primary amine and has the potential for hydrogen bonding, which is a stronger intermolecular force compared to dipole-dipole interactions. It also has a higher molecular weight compared to diethylamine. The presence of hydrogen bonding and a higher molecular weight makes it likely to have a higher boiling point than diethylamine.
4. \(n-C_4H_9OH\) - Butanol (D):
Butanol is an alcohol and can form hydrogen bonds. Hydrogen bonding is a strong intermolecular force, and compounds that can form hydrogen bonds generally have higher boiling points. Butanol also has a higher molecular weight compared to the three amines. Due to the presence of hydrogen bonding and a higher molecular weight, butanol is expected to have the highest boiling point among the given compounds.
So, the correct order of increasing boiling points is \( C < A < B < D \), and the correct option is (3) \( C < A < B < D \). |
