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9.2 MANUFACTURE OF AMMONIA AND ITS SALTSRadioactive

WHAT IS AMMONIA?Ammonia, orazane, is a compound of nitrogen and hydrogen with the formula NH3. It is a colourless gas with a characteristic and famous pungent smell.

USES OF AMMONIAThe use of ammonia, NH3, includes the manufacture of :1. Nitrogenous fertilisers2. Electrolyte in dry cells3. Nitric acid, HNO34. Cold pack (such as ammonium nitrate, NH3NO3)5. Cleansing agents (such as washing powders and detergents)6. Explosives (such as trinitrotoluene (TNT))

THE HABER PROCESSThe Haber process, also called the HaberBosch process, is the industrial implementation of the reaction of nitrogen gas and hydrogen gas. It is the main industrial procedure to produce ammoniaThe Haber Process was discovered by German chemist, Fritz Haber. In 1918, he won the Nobel Prize in Chemistry for this discovery.

WIE GEHT ES DIR?FRITZ HABERPROPERTIES OF AMMONIAProperties of Ammonia, NH3, include:Very soluble in waterPungent smellIs a colourless gasProduce thick white fumes with hydrogen chloride gas, HCl.Less dense than airChanges moist red litmus paper to blue (ammonia is an alkaline gas)Neutralizes acid to form salt Example: H2SO4 + 2NH3 (NH4)2SO4

MANUFACTURE OF AMMONIA BY HABER PROCESSIn the Haber Process, dry nitrogen gas, N2, and dry hydrogen gas, H2, are mixed in the mol or volume ratio to 1 to 3 (1:3)The gas mixture is then passed over iron fillings (catalyst) at temperatures from 450C and compressed under a pressure of 200 atmosphere to produce ammonia gas, NH3.N2 (g) + 3H2 (g) 2NH3 (g)Ammonia gas, NH3, obtained is cooled and condensed to form liquid ammonia, NH3 (aq)

SUMMARY OF HABER PROCESSN2 (g) + 3H2 (g) 2NH3 (g)Nitrogen is obtained by fractional distillitation of liquid air

Mole ratio (volume) of nitrogen to hydrogen is 1:3.

Hydrogen is obtained from natural gas methane, CH4.

Conditions:Temperature : 450CPressure: 200 atmosphereCatalyst: Iron fillings

PREPARATION OF AMMONIUM FERTILISERS IN THE LABORATORYNeutralisations reactions between aqueous ammonia , NH3 (ak), (alkali) and an acid solution to produce ammonium salts, NH4+, which can be used in fertilisers.Example:3NH3 + H3PO4 (NH4)3PO4 (Ammonium Phosphate)NH3 + HNO3 NH4NO3 (Ammonium Nitrate)2NH3 + H2SO4 (NH4)2SO4 (Ammonium Sulphate)

The apparatus set-up below can be used to prepare ammonium sulphate salt, (NH4)2SO4

1 mol of dm-3 ammonia solution, is drippled drop by drop into the sulphuric acid while stirring until the solution smells of ammonia (or red litmus paper turns blue).The solution is poured into the evaporating dish and the following steps are conducted.Heat the solution until saturated/concentratedCool down the solution until salt crystals formFilter salt crystalsRinse with a little distilled waterDry with filter paperH2SO4 (aq) + 2NH3 (aq) (NH4)2SO4 (aq)

BEAUTIFUL CHEMICAL REACTIONS! ENJOY