Acids Bases and Salts — Telangana (SSC) Class 10 Science Solutions (Free)

Acid: A substance that produces H⁺ ions (or H₃O⁺) when dissolved in water. Example: HCl → H⁺ + Cl⁻ Base: A substance that produces OH⁻ ions when dissolved in water. Example: NaOH → Na⁺ + OH⁻ Arrhenius definitions apply only in aqueous solutions

pH = -log₁₀[H⁺ concentration] It measures the acidity or alkalinity of a solution. Acidic solution: pH < 7 (example: pH = 2 for HCl) Neutral solution: pH = 7 (pure water) Basic/Alkaline solution: pH > 7 (example: pH = 10 for NaOH) Range: 0-14 (pH scale)

Strong acid: Completely ionizes in water, produces many H⁺ ions. Examples: HCl, H₂SO₄, HNO₃ Weak acid: Partially ionizes in water, produces few H⁺ ions. Examples: CH₃COOH (acetic acid), H₂CO₃ (carbonic acid) Strong acids have lower pH than weak acids of same concentration

Acid + Base → Salt + Water (Neutralization reaction) Example: HCl + NaOH → NaCl + H₂O Here: HCl is acid, NaOH is base Products: NaCl is salt (neutral), H₂O is water The H⁺ from acid combines with OH⁻ from base to form water

Salt: An ionic compound formed by neutralization of an acid with a base. Composition: Positive ions (cations) from base + negative ions (anions) from acid. Examples: 1. NaCl (sodium chloride) from HCl + NaOH 2. CuSO₄ (copper sulfate) from H₂SO₄ + Cu(OH)₂ 3. KNO₃ (potassium nitrate) from HNO₃ + KOH