NCERT Class VII Science Solutions: Chapter 5-Acids, Bases and Salts Part 3

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Question 14:

Paheli is suffering from indigestion due to acidity. Is it advisable to give her orange Juice in this situation and why?

Answer:

No. because orange Juice is acidic in nature. Instead she should be given an antacid which is base and neutralize the acidity. Milk of magnesia contains a base magnesium hydroxide which reacts with the acid and cures indigestion.

SHORT ANSWER QUESTIONS

Question 15:

Look at Figure which shows solutions taken in test tubes A, B, C and D. What colour is expected when a piece of red litmus paper is dropped in each test tube? Nature of the solutions is given in the table for your help.

As showing in images is a What colour is expected when a piece of red litmus paper

What Colour is Expected when a Piece of Red Litmus Paper

As showing in images is a What colour is expected when a piece of red litmus paper

Nature of Solution and Change in Colour of Red Litmus (Q)
Nature of Solution and Change in colour of red litmus (Q)

Test Tube

Nature of Solution

Change in colour

of red litmus

A.

Neutral

B.

Basic

C.

Acidic

D.

Neutral

Answer:

Nature of Solution and Change in Colour of Red Litmus (A)
Nature of Solution and Change in colour of red litmus (A)

Test Tube

Nature of Solution

Change in colour

of red litmus

A.

Neutral

No change

B.

Basic

Turn blue

C.

Acidic

No change

D.

Neutral

No change

Question 16:

While playing in a park, a child was stung by a wasp. Some elders suggested applying paste of baking soda and others lemon Juice as remedy. Which remedy do you think is appropriate and Why?

Answer:

Wasp sting inject a liquid in the skin which is acidic in nature. Hence, baking soda is the appropriate remedy, as it is basic in nature and neutralizes the acid.

Question 17:

Form a sentence using the following words - baking soda, ant bite, moist, effect, neutralized and rubbing.

Answer:

The effect of an ant bite can be neutralized by rubbing moist baking soda.