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Outline the principle for the preparation of ammonia by Haber process. How is nitric acid prepared from ammonia? Give equation. |
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Answer» Ammonia is manufactured industrially by Haber's process. N2 + 3H2 ⇌ 2NH3 +46.4 KJ mol-1 This is a reversible exothermic reaction. High pressure about 200 atm, low temp. 700 K and use of catalyst such as iron oxide with small amounts of Al2O3 and K2O would favour for formation of ammonia according to Le-chatelier's principle. Nitric acid prepared from ammonia: On large scale nitric acid is prepared by Ostwald's process. In this process, Ammonia undergo catalytic oxidation by atmospheric oxygen to give nitric oxide. 4NH3 + 5O2 → 4NO + 6H2O Nitric oxide combines with oxygen to give NO2 2NO + O2 ⇌ 2NO2 Nitrogen dioxide combines with oxygen to give NO2 2NO2 + O2 ⇌ 2NO2 Nitrogen dioxide dissolves in water to give nitric acid 3NO2 + H2O → 2HNO3 + NO In this way 98% HNO3 is obtained. |
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