NCERT Acids Bases Salts Objective Questions
NCERT Acids Bases Salts – Objective Questions (MCQs)
Class: 7 | Subject: Science | Section: Acids, Bases and Salts | Topic: NCERT Acids Bases Salts Objective Questions
Designed as per NCERT Syllabus | CBSE Board Examination Standard
Designed as per NCERT Syllabus | CBSE Board Examination Standard
1. Substances that taste sour are generally:
Answer: B. Acids
Acids like lemon juice and vinegar contain acidic substances which give a sour taste.
Acids like lemon juice and vinegar contain acidic substances which give a sour taste.
2. Bases that dissolve in water are called:
Answer: A. Alkalis
Water‑soluble bases such as sodium hydroxide are known as alkalis.
Water‑soluble bases such as sodium hydroxide are known as alkalis.
3. Which of the following is an acid?
Answer: B. Lemon juice
Lemon contains citric acid, making it acidic in nature.
Lemon contains citric acid, making it acidic in nature.
4. Which substance is basic?
Answer: C. Soap
Soap solutions are basic and feel slippery.
Soap solutions are basic and feel slippery.
5. Litmus solution is extracted from:
Answer: B. Lichens
Litmus is a natural indicator obtained from lichens.
Litmus is a natural indicator obtained from lichens.
6. Acids turn blue litmus:
Answer: B. Red
This colour change confirms acidic nature.
This colour change confirms acidic nature.
7. Bases turn red litmus:
Answer: A. Blue
Bases reverse the effect of acids on litmus.
Bases reverse the effect of acids on litmus.
8. The reaction between acid and base is called:
Answer: B. Neutralization
This reaction forms salt and water.
This reaction forms salt and water.
9. Which is formed after neutralization?
Answer: C. Neutralization always produces salt and water.
10. Hydrochloric acid reacts with sodium hydroxide to form:
Answer: A. Common salt and water are produced.
11. Tooth decay occurs due to formation of:
Answer: B. Bacteria produce acids that damage teeth.
12. Toothpaste is basic to:
Answer: B. It neutralizes mouth acids preventing decay.
13. Soil treated with quicklime reduces:
Answer: B. Lime neutralizes acidic soil.
14. Antacids contain:
Answer: B. They neutralize excess stomach acid.
15. China rose indicator turns green in:
Answer: B. It shows green colour in basic solutions.
16. Neutral solutions have pH value:
Answer: C. pH 7 represents neutrality.
17. Acid rain is harmful because it contains:
Answer: B. Sulphuric and nitric acids make rain acidic.
18. Which is NOT an indicator?
Answer: D. Sugar shows no colour change.
19. Neutralization reaction is generally:
Answer: B. Heat is released during reaction.
20. Factory waste is neutralized before disposal to:
Answer: B. Neutralization prevents environmental damage.
