Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. In inorganic chemistry, a nitrate is a salt of nitric acid with an ion composed of one nitrogen and three oxygen atoms (NO3-). In organic chemistry the esters of nitric acid and various alcohols are called nitrates. Nitrogen trioxide is an alternative name for nitrate. The nitrate ion is a polyatomic ion with the molecular formula NO 3 and a molecular mass of 62.0049 g/mol. It is the conjugate base of nitric acid, consisting of one central nitrogen atom surrounded by three identical oxygen atoms in a trigonal planar arrangement. The nitrate ion carries a formal charge of negative one, where each oxygen carries a 2 3 charge while the nitrogen carries a +1 charge, and is commonly used as an example of resonance. Almost all inorganic nitrate salts are soluble in water at standard temperature and pressure.