Acids, Bases and Salts, Class 10 Notes
Acids, Bases and Salts: All the substances around us are made of chemicals. Some of these chemicals taste sour, some taste bitter, and some are neutral. Based on their properties, substances are grouped as acids, bases, and salts.
What are Acids and their Importance?
Acids are substances that taste sour and turn blue litmus paper red. They are found in many food items we eat every day. For example, lemon juice, vinegar, curd, and oranges all contain acids. Acids can be natural or synthetic (man-made). Natural acids are found in plants and fruits, while synthetic acids are made in laboratories or industries.
| Examples of Acids | Where Found |
| Citric acid | Lemon, orange |
| Lactic acid | Curd, milk |
| Acetic acid | Vinegar |
| Tartaric acid | Tamarind |
| Hydrochloric acid (HCl) | Stomach |
| Sulphuric acid (H₂SO₄) | Industry |
Introduction To Bases With Examples
Bases are substances that taste bitter and feel soapy to touch. They turn red litmus paper blue. Bases are often used in cleaning products like soap and detergent. Some bases dissolve in water and are called alkalis. For example, sodium hydroxide and potassium hydroxide are alkalis.
| Examples of Bases | Use or Source |
| Sodium hydroxide (NaOH) | Used in making soap |
| Calcium hydroxide (lime water) | Used in whitewashing walls |
| Ammonium hydroxide (NH₄OH) | Used in window cleaners |
| Magnesium hydroxide | Used in antacids to reduce acidity |
How Salts are formed through Neutralization?
When an acid reacts with a base, both cancel each other’s effect and form a salt and water. This reaction is called neutralization.
Example:
Hydrochloric acid + Sodium hydroxide → Sodium chloride (salt) + Water
| Example of Salt | Use |
| Sodium chloride (NaCl) | Table salt for cooking |
| Sodium carbonate | Used in washing soda |
| Calcium carbonate | Used in chalk and cement |
Indicators To Test Acids, Bases and Salts
Indicators are substances that help us know whether a substance is an acid or a base.
| Indicators To Test Acids, Bases and Salts | ||
| Indicator | In Acid | In Base |
| Litmus | Red | Blue |
| Turmeric | Yellow | Reddish brown |
| China rose (Hibiscus) | Dark pink | Green |
