A salt is formed by acid + ?

**The reasoning** This is a fundamental **neutralization reaction** — one of the core concepts in chemistry. When an acid reacts with a base, they neutralize each other to produce a salt and water: **Acid + Base → Salt + Water** For example: - HCl (hydrochloric acid) + NaOH (sodium hydroxide) → NaCl (table salt) + H₂O - H₂SO₄ + 2NaOH → Na₂SO₄ + 2H₂O The acid donates H⁺ ions, the base donates OH⁻ ions, and together they form the salt and water. This is called a neutralization reaction because the acidic and basic properties cancel out. **Why the wrong options tempt you** **A) Acid** — Acid + Acid doesn't neutralize; you'd just get a mixture of acids, not a salt. **C) Salt** — This reverses cause and effect. Salt is the *product*, not the reactant. **D) Gas** — While some reactions produce gases, gas isn't the standard partner for forming salts from acids. **Quick takeaway** Remember: **"Acid meets Base, Salt takes place"** — neutralization always pairs an acid with a base to make salt and water.