SEBA Class 7 Science Important Chapter 3 Acidic Basic and Neutral Substances Found in Nature

SEBA Class 7 Science Important Chapter 3 Acidic Basic and Neutral Substances Found in Nature Solutions English Medium As Per SCERT New Syllabus to each chapter is provided in the list so that you can easily browse through different chapters SEBA Class 7 Science Important Chapter 3 Acidic Basic and Neutral Substances Found in Nature Notes and select need one. SEBA Class 7 Science Important Notes in English Download PDF. SCERT Class 7 Science (Amar Bijnan) Additional Solutions in English.

SEBA Class 7 Science Important Chapter 3 Acidic Basic and Neutral Substances Found in Nature

Also, you can read the NCERT book online in these sections Solutions by Expert Teachers as per Central Board of Secondary Education (CBSE) Book guidelines. SCERT Class 7 Science (Amar Bijnan) Extra Solutions in English are part of All Subject Solutions. Here we have given SCERT Class 7 Science Additional Notes in English for All Chapters, You can practice these here.

Acidic Basic and Neutral Substances Found in Nature

Chapter: 3

PART – I

IMPORTANT QUESTION ANSWER

Short-Type Questions and Answers:

1. What is the natural source of litmus? 

Ans: Litmus is a natural substance obtained from lichens.

2. How do acidic substances generally taste? 

Ans: Acidic substances usually have a sour taste.

3. What color change occurs when blue litmus paper is dipped in an acid? 

Ans: It turns red.

4. Define a neutral substance. 

Ans: A substance that is neither acidic nor basic and does not change the color of red or blue litmus paper is called a neutral substance.

5. Which acid is injected into the skin during a bee sting? 

Ans: A bee sting injects formic acid (also called methanoic acid) into the skin.

6. Name one olfactory indicator mentioned in the sources. 

Ans: Garlic, onion, or clove oil can be used as olfactory indicators because their smell changes in acidic or basic mediums.

7. What base is commonly used to treat indigestion caused by too much stomach acid? 

Ans: Milk of magnesia (magnesium hydroxide) is used to neutralise excess acid.

8. What is the result of a neutralisation reaction? 

Ans: The reaction between an acid and a base results in the formation of salt, water, and the release of heat.

9. What happens to red rose paper in a basic solution? 

Ans: Red rose paper strips turn green when exposed to a basic solution.

10. What acid is found in our stomach to help with digestion? 

Ans: Our stomach contains hydrochloric acid.

Fill in the Blanks:

1. Litmus is a natural indicator obtained from ___________.

Ans: Lichens.

2. Too much acid in the stomach leads to a painful condition called ______________.

Ans: Acidity.

3. The reaction between an acid and a base produces salt, water, and __________.

Ans: Heat.

4. Turmeric turns ___________ when it comes into contact with a basic solution.

Ans: Reddish-brown.

5. ___________ is often added to ponds and fisheries when the water becomes too acidic.

Ans: Slaked lime.

True or False:

1. Bases generally have a sour taste. 

Ans: False, Bases are generally bitter and slippery.

2. Lichens are organisms formed by the association of a fungus and an alga.

Ans: True.

3. Neutral substances turn blue litmus paper red. 

Ans: False, Neutral substances do not change the color of either litmus.

4. Formic acid is present in ant bites and bee stings.

Ans: True.

5. Turmeric is an excellent indicator for identifying acidic substances. 

Ans: False, Turmeric cannot differentiate between acidic and neutral substances; it only changes for bases.