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Inorganic Chemistry

Ostwald Process

Definition and meaning of Ostwald Process in chemistry.

The Ostwald Process is an industrial chemical method used for the large-scale production of nitric acid from ammonia and oxygen. It is a crucial step in the global manufacturing of fertilizers and explosives.

In more detail

The process occurs in two main stages. First, ammonia is oxidized with oxygen gas over a platinum-rhodium catalyst at high temperatures to form nitric oxide (NO). The nitric oxide is then cooled and further oxidized to nitrogen dioxide (NO2), which is subsequently absorbed in water to yield nitric acid. This process tightly links the Haber-Bosch process, which produces the necessary ammonia, to the global supply of industrial nitrates.

Key facts

FieldInorganic Chemistry
Compound FormulaHNO3
CatalystPlatinum-Rhodium alloy
Example

In a chemical plant using the Ostwald Process, a mixture of NH3 and O2 is passed over a platinum gauze at around 800 degrees Celsius to initiate the catalytic oxidation to NO.

Frequently asked questions

What is the catalyst used in the Ostwald process?

A platinum-rhodium alloy gauze is typically used to facilitate the initial oxidation step.

What is the primary raw material for the Ostwald process?

Ammonia, usually produced beforehand by the Haber-Bosch process.