ZIMSEC O Level Combined Science Notes: 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

To access more topics go to the Combined Science Notes page.