Bonding in ammonium chloride

Steps:

• Identify the reaction: NH₃ + HCl → NH₄Cl, forming ammonium ion.
• Break down NH₄Cl structure: ionic between NH₄⁺ and Cl⁻, internal bonds in NH₄⁺.
• Analyze NH₄⁺: tetrahedral with four N-H bonds, one formed by coordinate donation.
• Check geometry: NH₄⁺ has 109.5° angles; test other reactions.

Why B is correct:

• NH₄Cl features ionic bond (NH₄⁺—Cl⁻), three covalent N-H bonds, and one coordinate bond (N lone pair to H⁺), per VSEPR and Lewis theory.

Why the others are wrong:

• A: Ammonia forms ammonium salts with acids, not isolated ammonium ion.
• C: NH₄⁺ reacts with bases (e.g., OH⁻) to yield NH₃, not acids.
• D: Tetrahedral NH₄⁺ has 109.5° bond angles, not 107°.

Final answer: B