The key difference between nitrite and nitrate is that nitrite consists of one nitrogen atom and two oxygen atoms with a +3 oxidation state, and forms a weak acid, nitrous acid while, nitrate contains one nitrogen atom and three oxygen atoms with a +5 oxidation state, and forms a strong acid, nitric acid.
What is Nitrite?
The nitrite ion has the chemical formula NO₂⁻. Nitrite, particularly in the form of sodium nitrite, is commonly used in the chemical and pharmaceutical industries. It also plays a significant role as an intermediary in the nitrogen cycle in nature. Additionally, the term “nitrite” can refer to chemical compounds containing the -ONO group, which are esters of nitrous acid. The nitrite ion is the conjugate base of nitrous acid and consists of one nitrogen atom bonded to two oxygen atoms, arranged in a trigonal planar configuration.
Physical and Chemical Properties of Nitrite:
- Nitrite comprises one nitrogen atom and two oxygen atoms.
- Inorganic nitrites typically appear as colorless liquids or crystalline solids.
- Nitrous acid, a related compound, is highly volatile and primarily exists in the gas phase as a trans-planar molecule.
- Nitrous acid can also be found as a colorless liquid or crystalline solid.
What is Nitrate?
The nitrate ion, with the chemical formula NO3⁻, is a polyatomic anion. Nitrates are salts that contain this ion and are commonly used in fertilizers and explosives. Most inorganic nitrates are soluble in water, though bismuth oxynitrate is an example of an insoluble nitrate. The nitrate ion features a symmetrical structure with C2v symmetry, characterized by equal-length N-O bonds and a bond angle of approximately 115°. In valence bond theory, it is described as a resonance hybrid, with equal contributions from two canonical forms that are mirror images of each other. The nitrate ion carries a formal charge of -1.
Physical and Chemical Properties of Nitrate:
- The nitrate ion has the empirical formula NO3⁻ and a molecular mass of 62.01 daltons.
- It consists of one nitrogen atom centrally bonded to three identical oxygen atoms, forming a trigonal planar arrangement.
- There are no hydrogen bond donors.
- It has three hydrogen bond acceptors.
- There are no rotatable bonds present.
Nitrite vs Nitrate
The major difference between nitrite and nitrate is given below:
| Nitrate | Nitrite |
|---|---|
| Composed of one nitrogen atom and three oxygen atoms. | Composed of one nitrogen atom and two oxygen atoms. |
| The nitrogen has an oxidation state of +5. | The nitrogen has an oxidation state of +3. |
| Forms a strong acid known as nitric acid. | Forms a weak acid known as nitrous acid. |
| Exhibits a trigonal planar molecular geometry. | Exhibits a bent molecular geometry. |
| Can be reduced to nitrites. | Can be oxidized to nitrates. |
| Commonly used in fertilizers and explosives. | Commonly used in food preservatives. |