NCERT Solutions for Class 7 Science Chapter 4 Acids Bases and Salts - FREE PDF Download
FAQs on NCERT Solutions for Class 7 Science Chapter 4 Acids Bases and Salts
1. What is the difference between acids and bases as per NCERT Solutions for Class 7 Science Chapter 4?
- Acids taste sour, turn blue litmus red, and release H+ ions in water. Examples: Hydrochloric acid (HCl), citric acid.
- Bases taste bitter, feel soapy, turn red litmus blue, and release OH- ions in water. Examples: Sodium hydroxide (NaOH), ammonia (NH3).
2. How do natural indicators help to identify acids and bases, according to Class 7 Science Chapter 4?
Natural indicators such as litmus, turmeric, and china rose exhibit color changes in the presence of acids and bases. For example, litmus extracted from lichens turns red with acids and blue with bases. This helps to distinguish between acidic and basic substances easily.
3. Why is neutralization important in everyday life? Include an example from the Class 7 Acids Bases and Salts NCERT Solutions.
Neutralization prevents harm from excess acids or bases. For example, an antacid tablet is taken when suffering from acidity; the base in the tablet neutralizes excess stomach acid, relieving discomfort.
4. What role do acids, bases, and salts play in the neutralization reaction discussed in Science Class 7 Chapter 4 NCERT Solutions?
Acids and bases react during neutralization to form salt and water. The reaction removes the acidic and basic properties, making the solution neutral. For example: HCl + NaOH → NaCl + H2O.
5. How can Dorji identify acidic, basic, and neutral drinks using indicators as per NCERT Class 7 Science Chapter 4?
Dorji can test each drink with litmus paper. A drink turning blue litmus red is acidic, red litmus blue is basic, and no color change indicates a neutral drink.
6. Differentiate between strong and weak acids and bases based on Class 7 Science Chapter 4 Acids, Bases and Salts NCERT Solutions.
- Strong acids/bases completely dissociate into ions in water, e.g., HCl, NaOH.
- Weak acids/bases partially dissociate in water, e.g., acetic acid (CH3COOH), ammonium hydroxide (NH4OH).
7. What is the function of calamine lotion when applied after an ant bite, as explained in Chapter 4 NCERT Solutions?
Calamine lotion is basic and neutralizes the acid injected by the ant bite through a neutralization reaction, so it reduces irritation and itching on the skin.
8. Why must factory wastes be neutralized before releasing into water bodies, as highlighted in Acids Bases and Salts Class 7 Solutions?
Factory wastes can be acidic or basic and may harm aquatic life. Neutralizing them prevents environmental damage by ensuring waste is safe before disposal.
9. According to NCERT Solutions for Class 7 Science Chapter 4, how can you use turmeric as an indicator to differentiate between common substances?
Turmeric changes color in contact with a base (turns red), stays yellow with acids or neutral substances. This property helps recognize if a solution is basic or not.
10. What does it mean when blue litmus paper remains blue after being dipped in a solution, as per Science Class 7 Chapter 4 NCERT Solutions?
If blue litmus paper remains blue, the solution is either basic or neutral, since only acids will turn blue litmus red.
11. Why is distilled water considered neutral, and how can we verify it as per Class 7 Science NCERT Solutions?
Distilled water is neutral because it does not change the color of red or blue litmus paper. Testing a drop on litmus paper confirms this as the color remains unchanged.
12. What is a salt according to the NCERT Solutions for Class 7 Science Chapter 4, and can you give an example?
A salt is a compound formed when an acid reacts with a base during neutralization. A common example is sodium chloride (NaCl), produced by reacting hydrochloric acid and sodium hydroxide.
13. Explain how indicators work differently in acidic and basic solutions as per your NCERT Solutions for Class 7 Science Chapter 4.
Indicators like litmus, turmeric, and china rose show distinct color changes in acids and bases. For example, litmus turns red in acid, blue in base, and turmeric turns red only in base, not in acid.
14. What misconceptions do students commonly have about acids, bases, and salts in Class 7 Science, and how does the NCERT Solutions chapter clarify them?
Common misconceptions include thinking all acids are dangerous or that only chemical indicators work. The chapter clarifies that edible items like lemon juice are acids, and natural indicators can identify acids and bases safely.
15. How does the NCERT Solutions for Class 7 Science Chapter 4 help students prepare for CBSE exams?
The Solutions provide step-by-step answers, clarify conceptual doubts, and follow the CBSE pattern, equipping students for exam questions and boosting confidence in solving textbook exercises efficiently.











