Difference Between Nitrogen and Nitrate

The key difference between nitrogen and nitrate is that nitrogen is an element, while nitrate is a compound of nitrogen and oxygen.

Nitrates are highly available anionic forms containing nitrogen. Naturally, nitrogen exists as a gas, and it is the main reservoir of nitrogen. Plants cannot use this gaseous nitrogen directly, so some bacteria tend to convert gaseous nitrogen into water-soluble forms like nitrates, nitrites or ammonium. Atmospheric nitrogen is converted into nitrate through industrial fixation, from the action of lightning and by some of the soil microorganisms. We call this process nitrogen fixation. Ammonia and nitrites can also be converted to nitrate by the nitrifying bacteria in the soil. The nitrates in the soil are then absorbed by plants for their activities. Moreover, soil nitrates can convert back to nitrogen gas by the denitrifying bacteria like Thiobacillus denitrificans.

CONTENTS

1. Overview and Key Difference
2. What is Nitrogen 
3. What is Nitrate
4. Side by Side Comparison – Nitrogen vs Nitrate in Tabular Form
5. Summary

What is Nitrogen?

Nitrogen is the fourth most abundant element in our bodies. It is in group 15 of the periodic table with the atomic number 7. Nitrogen is a nonmetal and its electron configuration is 1s2 2s2 2p3. The p orbital is half-filled, giving nitrogen the capability to take three more electrons in order to achieve the stable noble gas configuration. Therefore, nitrogen is trivalent.

Two nitrogen atoms can form a triple bond between them, sharing three electrons form each. This diatomic molecule is in gas phase at room temperature and forms a colourless, odourless, and tasteless inert gas. Nitrogen is a non-flammable gas and does not support combustion. This is the most abundant gas in the earth’ atmosphere (about 78%).

Naturally, there are two isotopes of nitrogen, N-14 and N-15. N-14 is more abundant. At very low temperatures, nitrogen goes to the liquid state. It is similar to water in appearance, but the density is lower than water.

Nitrogen is widely useful in chemical industries and is a vital component needed for living organisms. The most important commercial use of nitrogen is its use as a raw material for ammonia, nitric acid, urea and other nitrogen compounds. These compounds may be incorporated in fertilizers because nitrogen is one of its major elements plants need for their growth. Nitrogen is also important in places where we need an inert environment, especially when doing chemical reactions. Moreover, liquid nitrogen is important for freezing things instantly and as a coolant in various devices (e.g.: computers).

What is Nitrate?

Nitrate is a polyatomic anion containing nitrogen and three oxygen atoms. The nitrogen atom is in the +5 oxidation state. The geometry of this molecule is trigonal planar, and it shows resonance as well. This monovalent anion can join with any other type of cation to form various organic and inorganic compounds.

Nitrate-containing compounds are often water-soluble and abundant in nature in soil, water and food. Nitrates are primarily important in making fertilizers. They are also important to make explosives. Nitrates are relatively non-toxic. Inside our bodies, nitrates convert into nitrites and therefore, it can become toxic.

What is the Difference Between Nitrogen and Nitrate?

Although the terms nitrogen and nitrate sound similar, they are very different terms. The key difference between nitrogen and nitrate is that nitrogen is an element, while nitrate is a compound of nitrogen and oxygen. In other words, nitrogen is the chemical element having the atomic number 7 and symbol N while Nitrate is an anion having the chemical formula NO₃^–. Moreover, nitrogen atom is trivalent while nitrate anion is monovalent. When considering the charge, the free nitrogen atom is neutral while nitrate anion has -1 charge. Furthermore, the oxidation state of free nitrogen atom is zero but in nitrate anion, it is +5.

Summary – Nitrogen vs Nitrate

Nitrogen is the chemical element having the atomic number 7 and symbol N and Nitrate is an anion having the chemical formula NO3-. The key difference between nitrogen and nitrate is that nitrogen is an element, while nitrate is a compound of nitrogen and oxygen.

Reference:

1. Powlson, D.s., and T.m. Addiscott. “NITROGEN IN SOILS | Nitrates.” Encyclopedia of Soils in the Environment, 2005, pp. 21–31., doi:10.1016/b0-12-348530-4/00905-x.

Image Courtesy:

1. “7 nitrogen (N) Bohr model” By Ahazard.sciencewriter – Own work (CC BY-SA 4.0) via Commons Wikimedia
2. “Nitrate-ion” By Benjah-bmm27 – Own work (Public Domain) via Commons Wikimedia