Synthesis of Nitric Oxide (Ostwald Process Step 1)

4NH3 + 5O2 → 4NO + 6H2O

Overview

Ammonia is catalytically oxidized over a platinum-rhodium gauze at 850 C to form nitric oxide and water. This is the first and critical step of the Ostwald process for nitric acid production. The catalyst operates at about 95% selectivity for NO.

Participants

Role Substance Coefficient State
Reactant Ammonia NH₃ 4 (g)
Reactant Oxygen O 5 (g)
Product Water H₂O 6 (g)

Everyday Example

The nitric acid used in fertilizer production and numerous industrial processes begins with this reaction.

Industrial Importance

The Ostwald process produces virtually all of the world's nitric acid (about 60 million tonnes annually), which is essential for fertilizers, explosives, and chemical synthesis.

Properties

Type
Synthesis
Reversible
No
Energy
Exothermic
ΔH
-905.2 kJ/mol
Catalyst
Platinum-rhodium gauze

Related Reactions

Fischer-Tropsch Synthesis (General) Formation of Aluminum Oxide Formation of Ammonia (Haber Process) Formation of Barium Oxide Formation of Barium Sulfate Formation of Beryllium Oxide Formation of Cadmium Oxide Formation of Calcium Carbonate from Oxides Formation of Calcium Hydroxide Formation of Calcium Oxide (Quicklime)

Frequently Asked Questions

What is the equation for Synthesis of Nitric Oxide (Ostwald Process Step 1)?
The balanced equation is: 4NH₃ + 5O₂ → 4NO + 6H₂O.
What type of reaction is Synthesis of Nitric Oxide (Ostwald Process Step 1)?
Synthesis of Nitric Oxide (Ostwald Process Step 1) is a synthesis reaction.
Is Synthesis of Nitric Oxide (Ostwald Process Step 1) exothermic or endothermic?
Synthesis of Nitric Oxide (Ostwald Process Step 1) is exothermic (releases energy). The enthalpy change (ΔH) is -905.2 kJ/mol.
What conditions are needed for Synthesis of Nitric Oxide (Ostwald Process Step 1)?
This reaction requires a catalyst (Platinum-rhodium gauze).