ICSE CHEMISTRY STUDY OF COMPOUNDS

ICSE CHEMISTRY CLASS 10 STUDY OF COMPOUNDS 

1. Hydrogen chloride gas dissolved using Funnel arrangement.

Ans: When HCl  gas is dissolved in water using Funnel arrangement, it prevents back-suction and provides large surface area for the absorption of HCl gas in water.

2. Quick lime is not used as drying agent in the purification of Hydrogen chloride gas.

Ans:  Quick lime is basic in nature and reacts with HCl gas to form Calcium chloride and Water.

3. Low temperature is maintained in the laboratory preparation of Hydrogen chloride gas.

Ans: High temperature causes fuel wastage and damage to the apparatus

4. Calcium hydroxide is taken in excess amount in the preparation of Ammonia gas in laboratory method.

Ans:  Excess Calcium chloride prevents the sublimation of Ammonium chloride

5. All glass apparatus is used in the laboratory preparation of Nitric acid.

Ans: Highly corrosive Nitric acid vapours attack and destroy rubber or Cork but not glass.

6. Nitric acid prepared in laboratory method appears in yellow colour.

Ans:  Nitric acid prepared in laboratory method contains dissolved Nitrogen dioxide gas in it.

7. Dilute Sulphuric acid can form two types of salts.

Ans: Sulphuric  acid is a dibasic acid

b) State one appropriate observation for each of the followings.

1. Silver nitrate solution is added to dilute hydrochloric acid then heated.

Ans: A white precipitate is obtained which disappears on heating.

2. Lead nitrate solution is added to dilute Hydrochloric acid followed by excess ammonium hydroxide.

Ans: A white precipitate is added which dissolves in excess Ammonium hydroxide solution.

3. Barium chloride solution is added to dilute Sulphuric acid.

Ans:  A white precipitate is formed

4. Excess Ammonia gas is passed into Copper sulphate solution.

Ans: A pale blue precipitate is formed which turns into inky blue solution.

5. Conc. Nitric acid is added to Copper turnings.

Ans: Reddish brown vapours and a blue filtrate is formed

6. Dilute Nitric acid is added to Copper turnings.

Ans: A blue filtrate is formed.

7. Conc. Sulphuric acid is added to Copper sulphate crystals.

Ans:  Blue colour of Copper sulphate fades and turns amorphous.

8. Conc. sulphuric acid is added to sugar crystals.

Ans: Turns into black spongy mass.

9. Dilute Sulphuric acid is added to Copper oxide.

Ans: A blue filtrate is formed.

10. A dilute acid is added to sodium carbonate.

Ans:  Brisk effervescence of a colourless gas which turns lime  water milky but has no effect on acidified KMnO₄ solution.

11. A dilute  acid is added to sodium sulphite.

Ans: A colourless gas with suffocating odour which turns lime water milky and decolourizes acidified KMnnO₄ solution.

12. A dilute acid is added to Sodium sulphide.

Ans:  A colourless gas with rotten egg smell which turns Lead acetate paper to silvery black.

c) Differentiate between

1. dilute Hydrochloric acid and dilute Sulphuric acid using Barium chloride solution.

Dilute HCl	Dilute Sulphuric acid
No precipitate is not formed with Barium chloride solution	A white precipitate is formed with Barium chloride solution

 

2. dilute Hydrochloric acid and dilute Sulphuric acid using Silver nitrate solution.

Dilute HCl	Dilute Sulphuric acid
A  white precipitate is formed with Silver nitrate solution which dissolves in excess Ammonium hydroxide solution	A white precipitate is formed with Silver nitrate solution which is insoluble in excess Ammonium hydroxide solution

 

3. Copper sulphate solution and dilute hydrochloric acid using Ammonium hydroxide

Copper sulphate solution	Dilute Hydrochloric acid
A pale blue ppt with small amounts of Ammonium hydroxide and inky blue solution with excess.	No precipitate with Ammonium hydroxide

 

d) Give Chemical tests of:

1. Dilute Hydrochloric acid with Lead nitrate

Ans:  A white precipitate is formed which disappears on heating

2. Conc. Sulphuric acid with Copper metal

Ans: A colourless gas with suffocating odour which turns lime water milky and decolourizes acidified KMnO₄

3. Ammonia gas with Copper sulphate solution

Ans: A pale blue precipitate with small amount of Ammonia gas passed into Copper sulphate solution and when excess ammonia gas passed turns inky blue solution.