Acids & Bases LEC‑30 | IGCSE / O‑L Chemistry 5070 | Sir Talha | 21th NOV скачать в хорошем качестве

Acids & Bases LEC‑30 | IGCSE / O‑L Chemistry 5070 | Sir Talha | 21th NOV

Acids and Bases (O-Level Chemistry) Acids are substances that produce hydrogen ions (H⁺) when dissolved in water. They have a pH below 7, taste sour, turn blue litmus paper red, and react with metals to form salt and hydrogen gas. Acids also react with bases to produce salt and water. Examples include hydrochloric acid (HCl), sulfuric acid (H₂SO₄), and nitric acid (HNO₃). Bases are substances that react with acids to form salt and water. A base that dissolves in water is called an alkali, and alkalis produce hydroxide ions (OH⁻) in solution. Bases have a pH above 7, turn red litmus paper blue, and feel soapy. Common alkalis include sodium hydroxide (NaOH), potassium hydroxide (KOH), and calcium hydroxide (Ca(OH)₂). The reaction between an acid and a base is called neutralisation, and it produces salt + water, for example: HCl + NaOH → NaCl + H₂O