Activity 2.14 Class10 Science

This activity explains the solubility and nature of different salts. It helps us understand how these salts react when dissolved in water.

Aim of the activity

Check the solubility of various salts in water and determine their nature.

Required materials

   1. Sodium chloride

   2. Potassium nitrate

   3. Aluminium   chloride

   4. Zinc sulphate

   5. Copper sulphate 

   6. Sodium   acetate

   7. Sodium carbonate

   8. Sodium hydrogen carbonate

   9. Distilled water

  10.  Beakers

  11.  Test tubes

  12.  Glass rod

  13. P^H paper and litmus paper

  14. Dropper

 

Procedure

We take about 1 g of each salt in separate test tubes and add 10 ml of distilled water to each test tube. Now we stir the solution with a glass rod and check the solubility of each salt.

Now we dip a strip of red and blue litmus paper into each salt solution and observe the colour change.

After that, we dip a p^H paper into each solution and compare the colour change with the p^H scale.

We identify the acid and base from which each salt is formed.

Observation

Table

S. No.	Salt	Formula	Solubility in water	Action on litmus	pH	Acid used	Base used
1	Sodium chloride	NaCI	soluble	no action	7	HCI	NaOH
2	Potassium nitrate	KNO3	soluble	no action	7	HNO3	KOH
3	Aluminium chloride	AICI3	soluble	no action	<7	HCI	AI(OH)3
4	Zinc sulphate	ZnSO4	soluble	no action	<7	H2SO4	ZnO
5	Copper sulphate	CuSO4	soluble	no action	<7	H2SO4	CuO
6	Sodium acetate	CH3COONa	soluble	no action	>7	CH3COOH	NaOH
7	Sodium carbonate	Na2CO3	soluble	no action	>7	H2CO3	NaOH
8	Sodium hydrogen	NaHCO3	soluble	no action	>7	H2CO3	NaOH

Explanation

Most of the salts are soluble in water because they dissociates in ions.

On the basis of p^H and litmus test, we can classify these salts into the following –

   1.  Acidic salts – These salts are formed from a strong acid and a weak base.

   2. Basic salts – These salts are formed from a weak acid and a strong base.

   3. Neutral salts – These salts are formed from a strong acid and a strong base.

The nature of salts depends on the strength of the acid and base.

Conclusion

 

We can conclude that -

   1.  Salts formed from different combinations of acids and bases show different p^H levels.

   2. The parent acid and base of salts.

   3. Acidic, basic and neutral nature of salts.

    Frequently Asked Questions

   1. Why do some salts show acidic behaviour and others show basic behaviour?

Answer – The acidic or basic behaviour of salts depends on the strength of the parent acid and base.

   2. Why do we use distilled water for testing the solubility of salts?

Answer – It does not interfere with the solubility of salts because it is neutral