Also known as spirit of niter or aqua fortis, nitric acid is a colorless, extremely corrosive acid. Chemically speaking, the acid is made of a hydrogen atom, nitrogen atom, and three oxygen atoms. The acid is a potent oxidizing agent, which means it’s more than willing to accept electrons from other substances. In general terms, this means the acid can erode or burn away any material it comes in contact with – including paper, rubber, fabric, cork, skin, etc. It can even dissolve metals such as iron, silver and copper.

Though primarily transparent in color, the acid may become yellowish if it has traces of water or nitrogen oxides. Pure nitric acids are not easily seen; commercial nitric acid has concentration levels of 68 percent. If the acidic property goes beyond 86 percent, the acid is called fuming nitric acid.

Uses/Applications

The acid is used to produce explosives, fertilizers, rocket fuels, etc. In fact, nitric acid is quite commonly used to manufacture fertilizer. The acid is used as a raw material and made to react with ammonia to churn out ammonium nitrate, a fertilizer. Nitric acid can also be used to make potassium nitrate, sodium nitrate, calcium nitrate, lithium nitrate, etc. In the polymer business, nitric acid helps make polyurethanes and polyamides. Though not known widely, nitric acid also helps remove magnesium and calcium deposits in factories that process dairy items.

A form of nitric acid called white fuming nitric acid (WFNA) is used to propel liquid-fueled rockets. WFNA is an extremely concentrated form of nitric acid, with concentrations more than 95 percent. Fuming nitric acid basically comprises dissolved nitrogen dioxide. There is another type of fuming nitric acid, called red fuming nitric acid (RFNA). Also, nitric acid should not be added to water bodies since it could deoxygenize water by promoting algae formation, causing significant harm to aquatic life, as a result.

Making Nitric Acid

Nitric acid is naturally found in rainwater. It can be manufactured using quite a few different chemical substances. For example, nitrogen dioxide when left to bubble in water leaves behind nitric acid. Nitrogen dioxide is made through a process called the Ostwald process. The process comprises a couple of stages that help make nitric acid from ammonia. The first stage entails oxidizing ammonia to make nitric oxide along with nitrogen dioxide. The second step is adding nitrogen dioxide to water that, as aforementioned, leaves behind nitric acid.