The key difference between cyanide and nitrile is that the term cyanide refers to any chemical compound containing a cyano group. Meanwhile, the term nitrile refers to any organic compound containing a cyano group.
We generally use the terms cyanide and nitrile interchangeably because both these terms refer to the C≡N group or the cyano group. But, they are different from each other because the term nitrile is used only for the organic compound having the cyano group while the term cyanide refers to both organic and inorganic compounds containing the cyano group.
CONTENTS
1. Overview and Key Difference
2. What is Cyanide
3. What is Nitrile
4. Side by Side Comparison – Cyanide vs Nitrile in Tabular Form
5. Summary
What is Cyanide?
Cyanide is any chemical compound having the cyano (C≡N) group. The cyano group has a carbon atom and a nitrogen atom, which are linked via a triple bond. Thus, the term cyanide may refer to any organic or inorganic compound containing the cyano group. In contrast, the term nitrile refers to any organic compound having a cyano group.
Figure 01: Structure of Hydrogen Cyanide
Usually, in inorganic cyanides, the cyano group is present as an anion; for example, sodium cyanide and potassium cyanide. Moreover, these cyanides are highly toxic. Hydrogen cyanide or HCN is a highly volatile and highly toxic substance. In nitriles, the cyano group is attached with a covalent bond to the rest of the molecule (not as an ion). A common example would be acetonitrile.
Moreover, cyanides are produced by many bacteria, fungi, and algae species. It is also a common component in many plants. Furthermore, these compounds form as a byproduct of combustion, in an oxygen-deficient environment.
When considering the applications of cyanides, these compounds are useful in mining for silver and gold because cyanides help to dissolve these metals. Furthermore, cyanides are important as precursors for the organic synthesis processes, e.g., production of nylon. Besides, there are applications of cyanide in the field of medicine and pest control.
What is Nitrile?
A nitrile is any organic compound having a –CN group, and a triple bond between a carbon atom and a nitrogen atom. The molecular structure of a nitrile is given as R-C≡N. Moreover, the bond angle of the R-C-N bond is 180o. Thus, functional groups of nitriles are linear structures.
Figure 02: Chemical Structure of a General Nitrile Compound
The nitrogen atom in nitrile is highly electronegative. Due to the difference in electronegativity values of carbon and nitrogen, a polarity is induced, making nitrile compounds polar. As these are polar molecules, nitriles have higher boiling points when compared to other molecules of the same size. Furthermore, nitrile compounds cannot form hydrogen bonds (if there are no other hydrogen bond-forming functional groups). Small nitrile compounds are soluble in water due to their polarity, but large nitrile compounds are not soluble.
Nitrile rubber, which is a synthetic polymer, is a common example of an industrially important nitrile. The monomers used for the production are acrylonitrile and butadiene. Products such as gloves made out of nitrile rubber have many advantages over natural rubber products. Such examples include chemical resistance, long shelf life, good puncture resistance, etc.
What is the Difference Between Cyanide and Nitrile?
We generally use the terms cyanide and nitrile interchangeably because both these terms refer to the C≡N group or the cyano group. Nevertheless, the key difference between cyanide and nitrile is that the term cyanide refers to any chemical compound containing the cyano group, whereas the term nitrile refers to any organic compound containing the cyano group.
Moreover, a further difference between cyanide and nitrile is that while the inorganic compounds have a cyano group as an anion, the organic compounds have a covalent bond between the molecule and the cyano group.
Summary – Cyanide vs Nitrile
The terms cyanide and nitrile are often used interchangeably since both these terms refer to the C≡N group or the cyano group. The key difference between cyanide and nitrile is that the term cyanide refers to any chemical compound containing the cyano group, whereas the term nitrile refers to any organic compound containing the cyano group.
Reference:
1. “Cyanide.” Wikipedia, Wikimedia Foundation, 17 Sept. 2019, Available here.
Image Courtesy:
1. “Hydrogen-cyanide-2D” By Hydrogen-cyanide.png: EricvseSVG-version: n-regen – Hydrogen-cyanide.png (Public Domain) via Commons Wikimedia
2. “Nitrile-group-2D” (Public Domain) via Commons Wikimedia