Paragraph 1 — Basicity

In aqueous solution, the basicity order of aliphatic amines is (1) > (2) > (3) > $NH_{3}$. This differs from the gas-phase order because of (4) effects. The conjugate acid of a tertiary amine, $R_{3}NH^{+}$, has three (5) groups that prevent effective hydrogen bonding with water. Aniline is a weaker base than aliphatic amines because its lone pair is (6) into the benzene ring.

Paragraph 2 — Preparation Methods

Gabriel phthalimide synthesis produces (7) amines only. It cannot be used to prepare aniline because aryl halides do not undergo (8) reactions. Hoffmann bromamide degradation converts $RCONH_{2}$ into $RNH_{2}$, meaning the product has (9) carbon(s) than the starting amide. The reagents used are $Br_{2}$ and (10).

Paragraph 3 — Diazonium Salt Reactions

Diazotization is carried out at (11) °C using $NaNO_{2}$ and HCl. In the Sandmeyer reaction, $ArN_{2}^{+}$ reacts with CuX to give (12). The ONLY reliable method for making aryl fluorides is the (13) reaction, which uses $HBF_{4}$. Azo coupling of diazonium salts with phenol requires (14) medium, while coupling with aniline requires (15) medium.