Neutralization requires an acidic starting solution

Steps:

• Sodium hydroxide (NaOH) is a strong base that increases pH.
• Adding NaOH to a solution produces a neutral solution with pH 7.
• Neutralization happens when a base reacts with an acid to form salt and water.
• Thus, the original solution must be acidic (pH < 7) for NaOH to neutralize it.

Why D is correct:

• By definition, neutralization adjusts an acidic solution (pH < 7) to pH 7 using a base like NaOH.

Why the others are wrong:

• A: NaOH is a base, not an acid; it reacts with acids, not alkalis.
• B: NaOH raises pH as a base, rather than lowering it.
• C: Neutral solution has pH 7, while pH 14 indicates a strong base.

Final answer: D