Difference Between Nitrogen and Nitrate

Main Difference – Nitrogen vs Nitrate

Nitrogen is a chemical element in the group 15 of the periodic table. It can form different types of molecules and ions by combining with different other elements such as hydrogen, oxygen, carbon, etc. Nitrate is one such ion in which a nitrogen atom is bonded to three oxygen atoms forming an anion. Nitrate ions can form different salt compounds by combining with different cations and covalent compounds such as esters of nitric acid. The main difference between nitrogen and nitrate is that nitrogen is a chemical element whereas nitrate is an anion.

Key Areas Covered

1. What is Nitrogen
     – Definition, Chemical Properties
2. What is Nitrate
     – Definition, Compounds of Nitrate
3. What is the Difference Between Nitrogen and Nitrate
     – Comparison of Key Differences

Key Terms: Amides, Ammines, Anion, Cation, Covalent, Nitrate, Nitrogen, Nitrogen Cycle, Oxygen, Relative Atomic Mass, Resonance

What is Nitrogen

Nitrogen is a chemical element in the group 15 of the periodic table and has the chemical symbol “N.” Nitrogen is a p block element according to its electron configuration; [He] 2s²2p³. The atomic number of nitrogen is 7, and the relative atomic mass is about 14 amu. At room temperature and standard pressure, nitrogen exists as a diatomic gaseous compound which is colorless, odorless and tasteless.

Figure 1: Atomic Structure of Nitrogen

Nitrogen has three unpaired electrons. It tends to form three covalent bonds in order to complete the electron shells. Nitrogen exists as N₂ gas in the atmosphere. It is a diatomic covalent compound.  There is a triple bond between the two nitrogen atoms.

Nitrogen has two stable isotopes: N-14 and N-15. But N-14 is the most stable and most abundant isotope. The abundance of this isotope is about 99%. Nitrogen forms a wide range of different compounds. Some examples include amides, amines, nitrates, nitrides,  azides, oxides, cyanide, etc.

Figure 2: Nitrogen Cycle

Nitrogen cycle shows the circulation of nitrogen in the environment. Nitrogen is an essential element for life on earth. It is included in the chemical composition of many important biological molecules such as nucleic acids, proteins, etc. Therefore, nitrogen occurs in the atmosphere, inside organisms, in the soil and is circulating between them.

What is Nitrate

Nitrate is an anion having the chemical formula NO₃^– . The molar mass of this ion is 62 g/mol. It is a covalent compound. In the Lewis structure, there are two oxygen atoms bonded to the nitrogen atom with single bonds and the other oxygen atom with a double bond. Therefore, nitrate ion has resonance structures. But the actual structure of this ion is a hybrid structure of all resonance structures. The geometry of the compound is trigonal planar.

Figure 2: Resonance Structures of Nitrate Ion

When nitrate ion is bonded to a proton, it is called nitric acid. Nitric acid is a key ingredient for most synthesis reactions in organic chemistry. For example, nitrobenzene is synthesized by reacting benzene with a mixture of nitric acid, sulfuric acid, and water.

Nitrate ion can be found in ionic compounds as salts, and as a free aqueous ion. Nitrate salts are common on earth as mineral deposits. Some examples include ammonium nitrate, sodium nitrate, potassium nitrate, etc. Salts of nitrate are ionic compounds composed of nitrate ion bonded to a cation. Covalent compounds of nitrate include esters of nitric acid.

In the nitrogen cycle, nitrifying bacteria (Nitrobacter) converts nitrite ions into nitrate ions. But denitrifying bacteria (such as Pseudomonas) can convert nitrate into nitrogen gas.

Difference Between Nitrogen and Nitrate

Definition

Nitrogen: Nitrogen is a chemical element in the group 15 of the periodic table and has the chemical symbol “N.”

Nitrate: Nitrate is an anion having the chemical formula NO₃^– .

Nature

Nitrogen: Nitrogen is a chemical element.

Nitrate: Nitrate is an anion.

Electrical Charge

Nitrogen: A nitrogen atom has no net electrical charge.

Nitrate: Nitrate ion has -1 charge.

Nitrogen Cycle

Nitrogen: Nitrogen element circulates in the nitrogen cycle in different forms such as ammonia, nitrite, and nitrate.

Nitrate: Nitrifying bacteria in nitrogen cycle converts ammonium ion into nitrate ion whereas denitrifying bacteria convert nitrate ion into nitrogen gas.

Compounds

Nitrogen: Nitrogen forms a wide range of different compounds including inorganic compounds and organic compounds.

Nitrate: Nitrate ion can be found in salts and in covalent compounds.

Conclusion

Nitrogen is a chemical element. Nitrate ion is an anion having -1 electrical charge. Nitrogen can be found circulating in the nitrogen cycle in different forms whereas nitrate ion can be found in the steps of nitrification and denitrification. The main difference between nitrogen and nitrate is that nitrogen is a chemical element whereas nitrate is an anion.

References:

 1. “Nitrogen – Element information, properties and uses | Periodic Table.” Royal Society of Chemistry – Advancing excellence in the chemical sciences, Available here.
2. “Nitrogen.” Wikipedia, Wikimedia Foundation, 2 Dec. 2017, Available here.
3. “Nitrate.” National Center for Biotechnology Information. PubChem Compound Database, U.S. National Library of Medicine, Available here.

Image Courtesy:

1. “Electron shell 007 Nitrogen” By Pumbaa (original work by Greg Robson) – File:Electron shell 007 nitrogen.png, (CC BY-SA 2.0 uk) via Commons Wikimedia
2. “Nitrogen Cycle 1” By Eme Chicano – Own work (CC0) via Commons Wikimedia
3. “Nitrate ion resonance structures” (CC BY-SA 3.0) via Commons Wikimedia