Question

GIVE YOUR OBSERVATIONS FOR FOLLOWING. WRITE CHEMICAL EQUATIONS ALSO.
1. Zinc strip is immersed in hydrochloric acid.
2. Mercuric oxide is heated.
3. Red lead is heated strongly.
4. Iron rod is immered in copper sulphate solution.
5. Silver nitrate solution is added to sodium chloride.

Answer 1

Explanation:

ANSWER

(i) When dilute hydrochloric acid is added to lead nitrate solution. white ppt of lead chloride appears.

Pb(NO

3

)

2

+HCl→PbCl

2

+2HNO

3

(ii) When barium chloride reacts with sodium sulphate solution, white ppt of barium sulphate is obtained.

BaCl

2

+Na

2

SO

4

→BaSO

4

+2NaCl

(iii) When conc. sulphuric acid is added to sugar crystals sugar charcoal is formed. Sugar charcoal is a black spongy mass. Conc. sulphuric acid is a super dehydrating agent and it sucks up all the water from the sugar.

(iv) When dilute hydrochloric acid is added to copper carbonate carbon dioxide is evolved.

CuCO

3

+HCl→CuCl

2

+H

2

O+CO

2

(v) When dilute hydrochloric acid is added to sodium thiosulphate sulphur dioxide gas is released.

Na

2

S

2

O

3

+2HCl→2NaCl+SO

2

+H

2

O+S