Examples and Uses of Acids/Bases/Salts MCQs Quiz | Class 10
This quiz covers Class X Science (Code 086), Unit I: Chemical Substances – Nature and Behaviour, specifically focusing on the topic “Examples and Uses of Acids/Bases/Salts”. It addresses daily life uses and safety awareness regarding these chemical substances. Complete the quiz to test your knowledge, check your score, and download the comprehensive answer key as a PDF for offline revision.
Overview: Acids, Bases, and Salts in Daily Life
Acids, bases, and salts play a crucial role in our everyday activities, from the food we eat to the cleaning agents we use. Understanding their properties and uses is a key part of the Class 10 Science curriculum under Unit I.
1. Common Acids in Natural Sources
Many naturally occurring substances contain acids. Here are some important examples:
- Vinegar: Contains Acetic Acid.
- Orange/Lemon: Contain Citric Acid.
- Tamarind: Contains Tartaric Acid.
- Tomato: Contains Oxalic Acid.
- Sour Milk (Curd): Contains Lactic Acid.
- Ant Sting/Nettle Sting: Contains Methanoic Acid (Formic Acid).
2. Important Salts and Their Uses
Salts formed from the neutralization of acids and bases have diverse industrial and domestic applications.
| Common Name | Chemical Formula | Key Uses |
|---|---|---|
| Common Salt | NaCl | Essential ingredient in food; raw material for caustic soda and chlorine. |
| Bleaching Powder | CaOCl2 | Disinfecting drinking water; bleaching cotton and linen in industries. |
| Baking Soda | NaHCO3 | Used in cooking (makes cakes soft); acts as an antacid. |
| Washing Soda | Na2CO3·10H2O | Removing permanent hardness of water; cleaning agent; glass manufacturing. |
| Plaster of Paris | CaSO4·½H2O | Supporting fractured bones; making toys and decorative materials. |
3. Importance of pH in Everyday Life
- Digestive System: Our stomach produces hydrochloric acid to help digestion. Excess acid causes indigestion, which is treated with antacids (mild bases like Magnesium Hydroxide).
- Tooth Decay: Decay starts when the pH of the mouth is lower than 5.5. Bacteria produce acids by degrading sugar left in the mouth. Using toothpaste (basic) helps neutralize excess acid.
- Self-Defence by Animals: Bee stings release methanoic acid causing pain. Applying a mild base like baking soda provides relief.
Quick Revision List
- Antacid: A base used to neutralize stomach acidity.
- Gypsum: Heated at 373 K to form Plaster of Paris.
- Chlor-Alkali Process: Used to produce Sodium Hydroxide from Sodium Chloride solution.
- Water of Crystallization: Fixed number of water molecules present in one formula unit of a salt (e.g., Copper Sulphate has 5).
Extra Practice Questions
- Why does distilled water not conduct electricity, whereas rain water does?
- What happens when bleaching powder is left open in air?
- Name the sodium compound which is used for softening hard water.
- What is the chemical formula of hydrated copper sulphate?
- Explain why sour substances like curd should not be kept in brass vessels.
