Red fuming nitric acid

Common card · No. 353907

Red fuming nitric acid (RFNA) is a strong and storage-stable oxidizer. It consists of nitric acid (HNO3), dinitrogen tetroxide (N2O4) and a small amount of water. The color of red fuming nitric acid is due to the dinitrogen tetroxide, which breaks down partially to form the reddish-brown nitrogen dioxide. The nitrogen dioxide dissolves until the liquid is saturated, and produces toxic fumes with a suffocating odor. RFNA increases the flammability of combustible materials and is highly exothermic when reacting with water. It is commonly used in bipropellant rockets as the oxidizer. It can also be a component of a monopropellant; with substances like amine nitrates dissolved in it, it can be used as the sole fuel in a rocket. This is inefficient and it is not normally used this way. Since nitrogen dioxide is a product of decomposition of nitric acid, its addition stabilizes nitric acid in accordance with Le Chatelier's principle. Addition of dinitrogen tetroxide also increases oxidizing power...

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