GSEB Solutions for Class 6 Science and Technology – Acid, Base and Salt

GSEB Solutions for Class 6 Science and Technology – Acid, Base and Salt (English Medium)

GSEB SolutionsMathsScience
Exercise 17:

Solution 1(a):

Solution 1(b):
Lemon juice, tomato juice, tamarind water, butter-milk, solution of citrate are acids.

Exercise 18:

Solution 1(a):
Lime water, solution of washing soda, Soap-water solution are bases.

Exercise 19:

Solution 1(a):
Salt solution, sugar dissolved solution and distilled water are neutral substances.

Exercise 20:

Solution 1(a):
Hibiscus paper is blue in colour and when it is dipped in the acidic solution, it turns red such as in case of blue litmus paper.

Turmeric paper is yellow in colour and when it is dipped in basic solution, it changes to red such as red litmus paper changes to blue in basic solution.

Thus, hibiscus paper behaves as blue litmus paper and turmeric paper behaves as red litmus paper.

Solution 1(b):
Hibiscus paper is blue in colour and when it is dipped in the acidic solution, it turns red like blue litmus paper.

Turmeric paper is yellow in colour and when it is dipped in basic solution, it changes to red like red litmus paper changes to blue in basic solution.

Thus, hibiscus paper behaves as blue litmus paper and turmeric paper behaves as red litmus paper.

Solution 1(c):
Acid changes blue litmus paper into red while there is no effect on red litmus paper.

Exercise 21:

Solution 1(a):
There is no effect of acid on phenolphthalein indicator.

Solution 1(b):

Base changes red litmus paper into blue while there is no effect on blue litmus paper.
On addition of two-three drops of phenolphthalein, it changes its colour to pink.

Exercise 22:

Solution 1(a):
There are red coloured palm impressions of both the palms on the dried sheet of paper. Soap water is a base which gives a red colour on reacting with turmeric powder.

Exercise 23:

Solution 1:

Solution 2.1:

Solution 2.2:

Solution 2.3:

Solution 3.1:

The properties of acid:

1. It changes the colour of blue litmus paper into red.
2. It is sour in taste.
3. On reaction with base, it forms salt and water.
   Examples: sulphuric acid, hydrochloric acid, nitric acid.

Solution 3.2:

The properties of base:

1. It changes the colour of red litmus paper into blue.
2. It is bitter in taste.
3. On reaction with acid, it forms salt and water.
4. It is adhesive (feel slippery).
   Examples: lime water, potassium hydroxide, sodium hydroxide.

Solution 3.3:

The properties of salt:

1. It does not have any effect on either blue or red litmus paper.
2. It is salty in taste.
   Examples: Common salt, edible soda, washing soda.

Solution 3.4:
Uses of acid:

1. It is used in the preparation of food.
2. It is used to clean tiles.

Solution 3.5:
Uses of base:

1. It is used in the preparation of food.
2. It is used for washing clothes.

Solution 3.6:
Uses of base:

1. Common salt is used in the preparation of food, preservation of dry food for a long duration and in the preparation of washing soda.
2. Edible soda is used as medicine of acidity, in fire extinguishing instruments and in the preparation of food.
3. Washing soda is used to remove dirt, washing clothes and vessels and in changing hard water into soft water.

Solution 3.7:
Sodium chloride is the main salt in the sea-water.

Solution 4:
Acid turns blue litmus into red and base turns red litmus into blue but salt solution does not have any effect on either blue or red litmus paper. Hence, they are called as neutral solutions. Sugar solution also does not have any effect on either blue or red litmus paper but sugar is not formed by the reaction between acid and base which means sugar is not salt. Thus, sugar is a neutral substance but not a salt. Hence, we can say that, “All neutral substances are not salt.”