Brønsted-Lowry acid-base proton transfer

Steps:

• Reaction: NH₃ + H₂O ⇌ NH₄⁺ + OH⁻.
• Water donates H⁺ to NH₃, making NH₄⁺.
• Brønsted-Lowry acid donates proton; base accepts it.
• Option D matches: water as proton donor.

Why D is correct:

• Water acts as acid by donating H⁺ to ammonia (Brønsted-Lowry definition: acid is proton donor).

Why the others are wrong:

• A: Both NH₃ (polar pyramidal) and NH₄⁺ (polar tetrahedral) have dipole moments.
• B: NH₃ bond angle is 107°; NH₄⁺ is 109.5° (opposite change).
• C: No electron transfer or oxidation state change; it's acid-base, not redox.

Final answer: D