Practicals

Question 1

Characteristics of Ammonia gas

Answer 1

Colourless gas with a characteristic pungent odour

Question 2

Tests for Carbon dioxide

Answer 2

Lime water test, along with passing the gas over either acidified potassium dichromate test or acidified potassium permanganate solution

Question 3

Give observation: When sulphur dioxide is passed over acidified potassium dichromate solution

Answer 3

Orange colour of the solution turns clear green

Question 4

Passing Ammonia gas through Nessler’s reagent: Observation

Answer 4

The colourless solution turns brown and a brown ppt is formed if excess ammonia is passed.

Question 5

Distinguish between: HCl and NH3

Answer 5

Litmus Test;
Pass the HCl through Lead (II) nitrate solution, curdy white ppt formed which dissolves on heating.
pass Ammonia gas through Nessler’s reagent
- Colourless solution turns brown and a brown ppt is formed if excess ammonia is passed.

Question 6

Carbon dioxide gas is passed through lime water in small amounts and then in excess. Write the chemical equation.

Answer 6

CO2 + Ca(OH)2 🡪 CaCO3 + H2O
Milky
3. CaCO3 + CO2 + H2O 🡪 Ca(HCO3)2
Soluble

Question 7

Pass Chlorine over moist

starch iodide paper: Observation

Answer 7

white paper turns blue

black