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Practical : 5
TITLE : Ammonia, Sulphuric Acid and Nitric Acid
Aim : To prepare ammonium salt fertilizer
Introduction : 1. Ammonium sulphate, chemical compound, (NH4)2SO4, a
colorless-to-gray, rhombohedral crystalline substance
that occurs in nature as the mineral mascagnite.
2. It is soluble in water and insoluble in alcohol or liquid
ammonia. It is prepared commercially by passing
ammonia, obtained from destructive distillation of coal,
into sulfuric acid and is used as a fertilizer, in preparing
other ammonium compounds, and for fireproofing.
3. Ammonia is manufactured in industry by the Haber
process. Nitrogen and hydrogen are mixed in the ratio
of 1: 3 volumes and passed over iron fillings (catalyst)
mixed with aluminium oxide (promoter) at 4500C –
5500C. The optimum pressure used in this process is
200 atmospheres.
4. Nitrogen is obtained from air by fractional distillation of
liquefied air.
5. Hydrogen is obtained from the reaction of steam with
charcoal or natural gas.
6. The use of low temperatures and high pressures is not
cost effective as the rate of production becomes slower,
even though the percentage production of ammonia
increases.
7. Thus the optimum temperature and pressure used here
are 4500C – 5500C and 200 atmosphere. About 15% of
NH3 is obtained in this way and the unreacted nitrogen
and hydrogen gases are recirculated through the
catalyst tower.
Materials / : Ammonia solution (2M), dilute sulphuric acid (1M), beaker,
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Apparatus glass rod, Bunsen burner, tripod stand, wire gauze, filter funnel
and filter
Procedure : 1. 30 cm³ of dilute sulphuric acid is poured into a beaker.
(Figure 1)
Figure 1
2. The ammonia solution is added little by little into the
beaker while stirring the solution. (Figure 2)
Figure 2
3. Did not add any ammonia solution when the solution
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smells amniotic.
4. The solution is heated until it become 1/3 of the original
volume.( Figure 3 and 4)
Figure 3 Figure 4
5. The solution is cooled in a mixture of ice and water.
(Figure 5) The salt crystals produced using the filter
funnel and filter paper.(Figure 6 and 7)
Figure 5
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Figure 6 Figure 7
Figure 8 : Preparation of ammonium salt fertilizer
Result :
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The white crystals formed are ammonium sulphate
Discussions :1. Write a balance equation to represents the formation of ammonium
sulphate in this experiment.
2 NH3 + H2 SO4 (NH4)2 SO4
2. How does the addition of ammonium sulphate affects the pH of the soil?
Untuk meneutralkan tanah atau mengurangkan keasidan tanah.
3. Beside fertilizers, ammonium sulphate is also used as an agriculture spray
adjuvant for water soluble pesticides. Explain the function of ammonium
sulphate in this area.
Ammonia digunakan sebagai bahan untuk menghasilkan racun serangga
perosak.
4. Name three examples of natural fertilizer which are used in farming.
a. Baja najis 5
b. Bahan bakar (kompos)
c. Baja organic
5. Name three examples of synthetic fertilizer which are used in agriculture.
a. Urea
b. Ammonium nitrat
c. Ammonium fosfat
6. Write chemical equations to represent the formation of:
a) ammonium phosphate
NH3 + H3 PO4 (NH4)2 PO4
b) ammonium nirate
NH3 + HNO3 NH4 NO3
c) urea
CO + 2NH3 CO (NH2)2 H2O
7. .Calculate the percentage of nitrogen in 1 mole of the fertilizers.
[Relative atomic mass: H,1; C,12; N,14; O,16; P,31; S,32 ]
Relative atomic Mass of nitrogen
% N = ---------------------------------------------------- X 100
Relative Molecular mass of fertiliser
a) ammonium phosphate
b) ammonium nirate
c) urea
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8. Which of the above fertilizer is the most suitable for the growth of plants?
Explains your answer.
Baja ammonium, ialah baja bernitrogen yang dapat membekalkan unsur
nitrogen untuk tumbuhan. Tidak balas peneutralan yang berlaku antara
larutan ammonia, NH3 (ak), dengan larutan asid menghasilkan garam
ammonium, NH4, yang dapat digunakan sebagai baja.
Conclusion :The white crystals formed are ammonium sulphate.
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http://www.mse.vt.edu/faculty/staley/2034/2034module.4.pdf
http://www.newagepublishers.com./sample.chapter/000627.pdf
http://www.freepatentsonline.com/6344066.html
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