Acid-base neutralization producing polar products

Steps:

• Write the reaction: NH₄Cl + NaOH → NH₃ + NaCl + H₂O in aqueous solution.
• Identify key products: NH₃ (ammonia) and H₂O (water) as molecular products.
• Assess polarity: Both NH₃ (trigonal pyramidal, μ ≈ 1.47 D) and H₂O (bent, μ ≈ 1.85 D) are polar.
• Evaluate options against reaction details.

Why A is correct:

• The reaction yields NH₃ and H₂O, two distinct polar molecules due to their asymmetric shapes and electronegativity differences (polarity defined by dipole moment > 0 D).

Why the others are wrong:

• B: Bond angle changes from 109.5° in tetrahedral NH₄⁺ to 107° in trigonal pyramidal NH₃.
• C: NH₄⁺ acts as an acid by donating H⁺ to OH⁻, per Brønsted-Lowry definition.
• D: Nitrogen oxidation state remains -3 in both NH₄⁺ and NH₃ (calculated as N surrounded by four H at +1 each).

Final answer: A