Class 7 Science Chapter 2: Exploring Substances: Acidic, Basic, and Neutral — practice questions with answers
Free practice for Class 7 Science, Chapter 2: Exploring Substances: Acidic, Basic, and Neutral. Try the solved questions below, then take a free test with instant marking and explanations.
31 questions9 easy, 15 medium, 7 hardNCERT · CBSE · State boards
Sample questions with solutions
Q1. Substances that turn blue litmus paper red are ______.
- acidic
- basic
- neutral
- metallic
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Answer: A. acidic
Why: Substances that turn blue litmus red are acidic; those that turn red litmus blue are basic. [p.10]
Why: Substances that turn blue litmus red are acidic; those that turn red litmus blue are basic. [p.10]
Q2. A sample turns red litmus paper blue. What is its nature?
- Basic
- Acidic
- Neutral
- Cannot tell
Show answer
Answer: A. Basic
Why: Turning red litmus blue shows a basic substance. [p.10]
Why: Turning red litmus blue shows a basic substance. [p.10]
Q3. Sugar solution does not change the colour of either litmus paper. It is ______.
- neutral
- acidic
- basic
- an indicator
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Answer: A. neutral
Why: Group C samples affect neither litmus paper — neutral substances. [p.9–10]
Why: Group C samples affect neither litmus paper — neutral substances. [p.9–10]
Q4. A substance that shows different colours in acidic and basic solutions is called an acid-base ______.
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Answer: indicator
Why: Litmus is an acid-base indicator. [p.10]
Why: Litmus is an acid-base indicator. [p.10]
Q5. Edible acidic substances like lemon juice and tamarind generally taste ______.
- sour
- bitter
- sweet
- salty
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Answer: A. sour
Why: Substances that taste sour tend to be acidic. [p.11]
Why: Substances that taste sour tend to be acidic. [p.11]
Q6. Baking soda solution feels soapy when rubbed between fingers. This shows it is ______.
- basic
- acidic
- neutral
- a metal
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Answer: A. basic
Why: Basic substances are generally slippery to touch. [p.11]
Why: Basic substances are generally slippery to touch. [p.11]
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Frequently asked questions
How many practice questions are there for Class 7 Science Chapter 2: Exploring Substances: Acidic, Basic, and Neutral?
31 questions (9 easy, 15 medium, 7 hard). A few are solved on this page; the free test shows the answer and explanation for every question after you submit.
Is this chapter from the NCERT book?
Yes — it follows the NCERT Class 7 Science syllabus, used by CBSE and many state boards.