9b_ammonia and its salts
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(B)
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Learning Outcomes
1. List the uses of ammonia
2. State the properties of ammonia
3. Explain the industrial process in themanufacture of ammonia.
4. Design an activity to prepare
ammonium fertilizer
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Uses of Ammonia
To manufacture
–fertilizer
– synthetic fibres
– Explosives
– Wood pulp
–Paints
– Varnishes
– Lacquers
– Rocket propellants
To be use as smelling salts to revivepeople who have fainted
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Properties of Ammonia, NH3
Is alkaline
Is a colourless gas
Has a pungent smell Is less dense than air
Burns in oxygen gas but not in the air
Is very soluble in water Gives a white fume when reacted with
hydrogen chloride gas, HCl
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Manufacture of Ammonia
Ammonia is manufacture in industriesthrough Haber Process.
Haber Process is invented by Fritz Haber(1868 – 1934) in year 1918 who wasawarded the Noble Prizes.
This process combines N2 from the air withH2 to form ammonia, NH3.
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Manufacture of Ammonia
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The ratio of volume N2 : H2 = 1 : 3
This means 1 volume of nitrogen gas is mixedwith 3 volume of hydrogen gas in the reactor.
N2 (g) + 3H2 (g)
2NH3(g)
The production of ammonia gives out heat.
450C, Fe
200 atm
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The reaction to produce ammonia, NH3 isreversible.
The unreacted N2 and H2 are recycled andpassed back into the reactor together withthe new source of N2 and H2 .
About 98% of N2 and H2 are converted intoammonia.
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Preparation of Ammonium Fertilizers
Aim : To prepare an ammonium fertilizer
Apparatus:
25.0cm3
pipette, pipette filler, 250 cm3
conical flask,burette, retort stand with clamp, white tile, 250 cm3 beaker, glass rod, filter funnel, Bunsen burner,evaporating dish, spatula
Materials:1.0 mol dm3 sulphuric acid, 2.0 mol dm3 ammoniasolution, methyl orange, filter paper, distilled water
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Procedure:(A) Titration ( to determine the volume of NH3 solution
needed)
1. Fill a clean burette with sulphuric acid. Record the initial burettereading.
2. Pipette 25.0 cm3 of ammonia solution into a conical flask
3. Add 2 to 3 drops of methyl orange to the ammonia solution.The solution turns yellow.
4. Add sulphuric acid form the burette slowly until the solution justturns orange.
5. Record the final burette reading.
6. Calculate the volume of acid needed to neutralize 25.0 cm3 ofammonia solution ( let the volume be V cm3 )
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(B) Preparation of Ammonium sulphate
1. Pipette 25.0 cm3 of ammonia solution into a conical flask. ( Do not
add indicator )
2. From the burette, add exactly V cm3 of sulphuric acid to the ammoniasolution.
3. Pour the contents of the conical flask into a evaporating dish.
4. Gently heat the solution until it is saturated. Allow the saturatedsolution to cool so that the salt crystallises.
5. Filter the solution to obtain the crystals.
6. Wash the crystals with a little of distilled water. Then, dry the crystalwith a filter paper.
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