NCERT Solutions for Class 7 Science Chapter 5 Acid Base and Salt

NCERT Solutions For Class 7 Science Chapter 5 PDF Free Download

The NCERT solutions class 7 Science Chapter 5 Acids, Bases and Salts is crucial due to the applications it has in science and the impact it puts on your future studies as well as on CBSE Class 7 examinations. The NCERT solutions provided here are comprehensive and help to understand the concepts for students who are struggling to remember the concepts of Acids, bases and salts for a longer time.

NCERT extra questions for Class 7 Science Chapter 5 prepared by BYJU’S will help you understand the topic easily. Through its interactive teaching models, BYJU’S will assist you in remembering the topic for a long time.

Download PDF of NCERT Solutions for Class 7 Science Chapter 5 – Acids, Bases and Salts

NCERT solutions class 7 science chapter 5 part 1
NCERT solutions class 7 science chapter 5 part 2
NCERT solutions class 7 science chapter 5 part 3

Access Answers to NCERT Solutions for Class 7 Science Chapter 5 – Acids, Bases and Salts

Exercise Questions

1. State differences between acids and bases.

Solution:

Acids

Bases

Acids are sour in taste

Bases are bitter in taste

Acids turn blue litmus paper into red color

The base does not change the colour of blue litmus paper

Acids does not change the colour of the red litmus

Bases turn red litmus paper to blue color

Acids do not change the colour of turmeric

Bases turn turmeric to red

2. Ammonia is found in many household products, such as window cleaners. It turns red litmus blue. What is its nature?

Solution:

The answer is basic in nature

3. Name the source from which litmus solution is obtained. What is the use of this solution?

Solution:

Litmus solution is extracted from lichens. Litmus solution is used as an indicator to find acidic and basic nature of a solution.

4. Is the distilled water acidic/basic/neutral? How would you verify it?

Solution:

Distilled water is neutral in nature, and this can be tested by using red and blue litmus paper. In either of the cases, colour remains unchanged.

5. Describe the process of neutralisation with the help of an example.

Solution:

Neutralisation is a reaction between an acid and a base. Here both acids and bases get neutralised For example, when sodium hydroxide (NaOH) is added to hydrochloric acid (HCl), sodium chloride (NaCl) and water (H2O) are obtained.

 NaOH + HCl → NaCl + H2O + Heat

6. Mark ‘T’ if the statement is true and ‘F’ if it is false:

(i) Nitric acid turn red litmus blue. (T/F)

(ii) Sodium hydroxide turns blue litmus red. (T/F)

(iii) Sodium hydroxide and hydrochloric acid neutralise each other and form salt and water. (T/F)

(iv) Indicator is a substance which shows different colours in acidic and basic solutions. (T/F)

(v) Tooth decay is caused by the presence of a base. (T/F)

Solution:

i) False

ii) False

iii) True

iv) True

v) False

7. Dorji has a few bottles of soft drink in his restaurant. But, unfortunately, these are not labelled. He has to serve the drinks on the demand of customers. One customer wants acidic drink, another wants basic and third one wants neutral drink. How will Dorji decide which drink is to be served to whom?

Solution:

Dorji can taste a few drops out of soft drinks bottles, acidic solution is sour in taste, basic solution is bitter in taste, and the neutral solution has no taste. Along with tasting, Dorji can use litmus paper to test the nature of soft drink. He should use blue litmus paper to test the acidic solution. Dorji has to put a drop of solution on blue litmus. If it turns red then the solution will be acidic in nature.

Similarly, he can use red litmus paper to test the basic solution. He has to put a drop of solution on red litmus. If it turns blue then the solution will be basic in nature.

8. Explain why:

(a) An antacid tablet is taken when you suffer from acidity

(b) Calamine solution is applied on the skin when an ant bites.

(c) Factory waste is neutralised before disposing it into the water bodies.

Solution:

  1. The antacid tablet contains base like milk of magnesia which neutralises the acid produced in the stomach. Hence, it is used while suffering from acidity.
  2. When ant bites, it injects formic acid inside the skin. Calamine consists of Zinc carbonate which is basic in nature. Hence calamine neutralises the effect of formic acid to bring relief for the affected person.
  3. Factory wastes are acidic in nature which may cause harm to the aquatic life. Hence, they are neutralised by using a base before disposing it into the water bodies.

9. Three liquids are given to you. One is hydrochloric acid, another is sodium hydroxide and third is a sugar solution. How will you identify them? You have only turmeric indicator.

Solution:

Add solution to container with turmeric indicator. If the solution is NaOH, it would turn turmeric indicator to red. To the same container, add test solution number 2. If the added solution is sugar solution indicator remains red because mixture of basic and neutral solution will remain basic in nature.

Similarly, add the test solution number 3 to another container with turmeric indicator. If the indicator remains red then the solution will be hydrochloric acid.

10. Blue litmus paper is dipped in a solution. It remains blue. What is the nature of the solution? Explain.

Solution:

Above solution may be neutral or basic in nature as both of them will not change the colour of the blue litmus paper.

11. Consider the following statements:

(a) Both acids and bases change colour of all indicators.

(b) If an indicator gives a colour change with an acid, it does not give a change with a base.

(c) If an indicator changes colour with a base, it does not change colour with an acid.

(d) Change of colour in an acid and a base depends on the type of the indicator. Which of these statements are correct?

(i) All four

(ii) a and d

(iii) b, c and d

(iv) only d

Solution:

Only d) is correct

Important topics covered in NCERT Solutions for class 7 chapter 5 Acids bases and salts

Section Number

Topic

1

Acids And Bases

2

Natural Indicators Around Us

3

Neutralisation

4

Neutralisations In Everyday Life

The combination of acid and base results in the formation of salts which can either be acidic, basic or neutral in nature. This process is known as neutralisation. Neutralization is a very important topic with respect to examination. To avoid confusion between acids, bases and salts make a comparison table of them.

Acids, bases and salts are common in our everyday life. It is important to know its properties to exploit its advantages and to prevent its dangers. From the exam point of view, neutralisation and its application are important. All the topics in the chapter are covered in the Class 7 NCERT Solutions for Chapter 5 Science. Download the free PDF provided here, if necessary, take a printout to keep it handy during the preparation of exams.

BYJU’S is India’s largest K-12 learning app with top-notch teachers from across the nation with excellent teaching skills. Find notes, question papers for various other subjects like Mathematics, Biology, Chemistry and many competitive exams as well. Enjoy learning with a great experience. Stay tuned to know more about NCERT Solutions and preparation tips. To know more about NCERT solutions you can register with BYJU’S or download our app for simple and interesting content.

Frequently Asked Questions on Acids, Bases and Salts

Name the source from which litmus solution is obtained?

Litmus solution is extracted from lichens. Litmus solution is used as an indicator to find acidic and basic nature of a solution.

Is the distilled water acidic/basic/neutral?

Distilled water is neutral in nature, and this can be tested by using red and blue litmus paper. In either of the cases, colour remains unchanged.

Describe the process of neutralisation?

Neutralisation is a reaction between an acid and a base. Here both acids and bases get neutralised For example, when sodium hydroxide (NaOH) is added to hydrochloric acid (HCl), sodium chloride (NaCl) and water (H2O) are obtained.

Ammonia is found in many household products, such as window cleaners. It turns red litmus blue. What is its nature?

The answer is basic in nature

2 Comments

  1. I liked it!!

  2. I like it

Leave a Comment

Your email address will not be published. Required fields are marked *