A20 Oxidation of Nitric Oxide by Oxygen

Description
Two volumes of nitric oxide and one volume of oxygen react to form a red brown gas. The total volume of the products is less than the initial volume of nitric oxide. All gases are contained in syringes with volume calibrations that are clearly visible.

Equation
2 NO + O₂ --> 2 NO₂

2 NO₂ <--> N₂O₄

Reference