2P2 Group 9 --- 2P07 Answer Scheme

Colour of gas:

Sodium Hydroxide + Ammonium chloride: Colourless

Calcium hydroxide + ammonium nitrate: Colourless

Odour:

Sodium~: pungent

Calcium~: pungent

Damp Red litmus paper:

Sodium~: Turns blue

Calcium~: Turns blue

Damp blue litmus paper:

Sodium~: Remains blue

Calcium: Remains blue

Name of gas formed: Ammonia

Conclusion

1)      Ammonia

2)      Alkali + ammonium salts = salt + water + ammonia gas

3)      The mixture must be heated to evaporate the ammonia gas from the solution

4)      Ammonia gas is alkaline in nature

5)      Alkalis only show its properties in water

6)      Heat a mixture of X and sodium hydroxide. If x is ammonia salt, there would be a colourless and pungent gas. It would turn red litmus paper blue. The gas would be ammonia gas.

7)      Ammonium nitrate can react with calcium hydroxide to form calcium nitrate, water and ammonia.

Exercise:

1a) sodium hydroxide + ammonium chloride à sodium chloride + ammonia + water

b) NaOH + NH4Cl à NaCl + NH3 + H2O

2a) sodium hydroxide + ammonium sulfate à sodium sulfate + ammonia + water

b) 2NaOH + (NH4)2SO4 à Na2SO4 + 2NH3 + 2H2O

3a) sodium hydroxide + ammonium nitrate à sodium nitrate + ammonia + water

b) NaOH + NH4NO3 à NaNO3 + NH3 + H2O

4a) calcium hydroxide + ammonium chloride à calcium + ammonia + water

b) Ca(OH)2 + 2NH4Cl à CaCl2 + 2NH3 + 2H2O

5a) calcium hydroxide + ammonium sulfate à calcium sulfate + ammonia + water

b)  Ca(OH)2 + (NH4)2SO4 à CaSO4 +2NH3 + 2H2O

6a) calcium hydroxide + ammonium nitrate à calcium nitrate + ammonia + water

b) Ca(OH)2 + 2NH4NO3 à Ca(NO3)2 + 2NH3 + H2O