Model Answers for 2P07

2P07.
Observations
                       Sodium hydroxide+ammonium chloride        Calcium hydroxide +ammonium nitrate
Colour of gas                  Colourless                                                    Colourless
Odour of gas                   Pungent                                                        Pungent
Effect of gas on damp
: Red Litmus Paper          Turns Blue                                                    Turns blue
: Blue Litmus Paper          No visible change is observed.                    No visible change is observed.
Name of gas formed        Ammonia                                                      Ammonia

Conclusion (answers)
1. ammonia
2.Alkali+ammonium salt -->salt+water+ammonia gas
3.It is necessary to warm the mixture to evaporate ammona gas from the solution.
4. Ammonia gas is alkaline in nature.
5.An alkali only shows its alkaline properties in the presence of water.
6.Heat a mixture of substance X and sodium hydroxide .If X is an ammonium salt , a colourless and pungent gas which turned moist red litmus paper blue will be observed. The gas is ammonia.
7. Ammonium nitrate can react with calcium hydroxide to form calcium nitrate ,water and ammonia.

Exercise
1. sodium hydroxide+ammonium chloride->sodium chloride+water+ammonia gas
  NaOH+NH4CL->NaCL+H20+NH3
2. sodium hydroxide+ammonium sulfate->sodium sulfate+water+ammonia gas
(NH4)2 SO4 -> Na2SO4->2H20+2NH3
3.sodium hydroxide +ammonium nitrate  --------->sodium nitrate + water +ammonia gas
NaOH+NH4NO3 --------->NaNO3+H2O+NH3
4.calcium hydroxide +ammonium sulfate  --------->calcium sulfate +water +ammonia gas
Ca(OH)2 + 2NH4Cl --------->CaCl2+2H2O+2NH3
5.calcium hydroxide + ammonium sulfate  --------->calcium sulfate+water +ammonia gas
Ca(OH)2 +(NH4)2SO4 --------->CaSO4 +2H20 +2NH3
6.calcium hydroxide +ammonium nitrate  ---------> calcium nitrate +water+ammonia gas
Ca(OH)2 + 2NH4NO3  --------->Ca(NO3)2+2H2O+2NH3

BY LIM WAN JIE   GOH HAO WEI   THIO TENG KIAT