Fertilizer (1/4)

Fertilizer

A)Definition

A fertilizer is a chemical compound added to the soil to supply plants with the ______( essential ______)they need to grow. The most important elements are ______, ______and ______.

B)Reasons of using fertilizers

1)______agricultural yield and ______of crops

2)replace the essential elements which have been removed when plants are grown and harvested.

C)Natural Source of Nitrogen

______causes nitrogen and oxygen in the air to react to form oxides of nitrogen then nitric acid. Nitric acid provides nitrate ions for plants.

However, natural methods usually don’t replace the soil with nitrogen fast enough.

D)Types of Fertilizers

The most important fertilizer is ______fertilizer. It is because nitrogen is essential for synthesis of ______and ______. It is also necessary for strong, healthy ______and ______.

e.g. / Ammonium nitrate / Ammonium sulphate
Sodium nitrate / Potassium nitrate
Ammonia solution / Urea
NPK fertilizer

E)Nitrogen Content in Nitrogenous Fertilizer

Calculate the percentage of nitrogen by mass in ammonium nitrate.

The relative formula mass of ammonium nitrate =

Therefore, each ______g of ______contains ______g nitrogen

Thus, percentage of nitrogen =

Ammonium nitrate contains ______by mass of nitrogen.

In general, % mass of nitrogen in a fertilizer

=  100%

C.W. Which of the following fertilizers has the highest nitrogen content?

NH3, (NH4)2SO4, NaNO3

F)Manufacture of Nitrogenous Fertilizers

e.g. + →(NH4)2SO4(s)

+ →NH4NO3(s)

Steps: 1)

2)

3) Filtration

G)Manufacture of Ammonia

Industrial process to produce ammonia cheaply on a large scale: ______.

It is a reaction between ______and ______under special condition and this reaction is ______. It is an ______reaction.

Source of hydrogen: reacting ______or ______with ______.

Source of nitrogen: fractional distillation of ______.

Reaction condition: 1) ______temperature and pressure

2) Catalyst: ______

H)Laboratory Preparation and Uses of Ammonia

Ammonia gas can be prepared by heating an ammonium salt with an alkali.

Ammonium salt + alkali →salt + ammonia + water

e.g.

Ammonia is colourless and has a characteristic pungent choking smell. It is ______and lighter than air. It is very soluble in water and it is an ______gas. It turns wet ______litmus paper ______.

Uses of Ammonia:1) Making ______e.g. NH4NO3

2) Making nitric acid

3) It is present in glass cleaners, it can ______grease to form a soap as it is alkaline. Thus the grease can be removed.

I)Nitric Acid

Nitric acid is made by the Ostwald process.

Raw materials: ammonia, air and water.

The equations for the reactions are as follow:

Uses of Nitric Acid:1) Making ______e.g. NH4NO3

2) Making ______

3) Making ______

4) Making ______

J)Sulphuric Acid

It is made by the ______process.

1) Preparation of sulphur dioxide

a) Burning sulphur in air

ORb) Roasting sulphide ores in air

e.g.

2) Catalytic Oxidation of Sulphur Dioxide to Sulphur Trioxide

It is a ______reaction and it is ______.

Reaction condition: 1) High ______

2) Room ______

3) Catalyst: ______

3) Conversion of Sulphur Trioxide to Sulphuric Acid

Sulphur trioxide is dissolved in concentrated sulphuric acid to form ______(______), H2S2O7. Oleum is then diluted with ______to make concentrated sulphuric acid.

Uses of Sulphuric Acid:1) Making ______e.g. (NH4)2SO4

2) Making additives in white paints e.g. ______

3) Making synthetic fibres

4) Making ______.

K)Properties of Sulphur Dioxide

It is a ______gas. It has a characteristic choking smell. It is poisonous and very ______in water.

It is an acidic gas which turns wet ______litmus paper ______.

It is a reducing gas which reacts with strong oxidizing agent such as acidified ______.