How It’s Used Nitrogen dioxide (aka nitrogen peroxide) exists in equilibrium with its dimer dinitrogen tetroxide. It presents as a reddish brown gas or yellowish-brown liquid when cooled or compressed. The compound is an intermediate in nitric acid production; a nitrating agent in explosives; a polymerization inhibitor for acrylates; and an oxidizing agent in rocket … Continue reading Nitrogen Dioxide—and Nitrogen Dioxide Monitoring Instrumentation