The production of Nitric acid

• Some of the ammonia produced using the Haber process is used in the production of nitric acid
• The first stage in the process of making nitric acid is the oxidation of ammonia
• To form nitric acid
• \text{ammonia + oxygen} \rightarrow\text{nitric oxide+ water+heat}
• This an exothermic reaction
• It is thus necessary to cool the products to about 150°C
• After cooling the nitric acid is mixed with excess air and passed slowly over a catalyst
• Platinum/rhodium is used as a catalyst
• It is oxidized to nitrogen dioxide
• This reaction is exothermic
• The heat is absorbed in heat exchangers and used in other parts of the factory where heat is required
•  \text{nitric oxide+oxygen}\rightarrow\text{nitrogen dioxide+heat}
• The nitrogen dioxide and excess air is absorbed into water to form nitric acid
• \text{oxygen(from air)+ water +nitrogen dioxide}\rightarrow\text{nitric acid}
• Nitric acid is used to make
• Fertilizers
• explosives and
• dyes

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