Class 10 Science Chapter 2 – Acids, Bases and Salts (Full NCERT Notes PDF)

Class 10 - Chapter 2: Acids, Bases and Salts (NCERT Notes)

1. Acids and Bases Basics

- Acids: Sour in taste, turn blue litmus red.

- Bases: Bitter in taste, turn red litmus blue.

- Indicators:

* Natural: Litmus, turmeric, red cabbage.

* Synthetic: Methyl orange, phenolphthalein.

* Olfactory: Onion, vanilla, clove.



2. Chemical Properties

- Acid + Metal -> Salt + Hydrogen Gas

- Base + Metal -> Salt + Hydrogen Gas (some metals only)

- Acid + Metal Carbonate -> Salt + CO2 + Water

- Acid + Base -> Salt + Water (Neutralisation)

- Metal Oxide + Acid -> Salt + Water

- Non-metallic Oxide + Base -> Salt + Water



3. Ions in Solution

- Acids release H+ ions in water -> acidity

- Bases release OH- ions in water -> basicity

- HCl gas alone not acidic, needs water to release H+



4. Strength of Acids and Bases

- Measured by pH scale (014):

* pH < 7 -> Acidic

* pH = 7 -> Neutral

* pH > 7 -> Basic

- Universal Indicator shows exact pH



5. Importance of pH in Daily Life

- Stomach acid (HCl) helps digestion; antacids neutralise excess acid.