Difference Between Organic and Inorganic Chemistry

Difference Between Organic and Inorganic Chemistry

In a broad view, chemistry can be classified as a branch of physical science that explains the origin, structure and behaviour of matter and the change of matter from one form to another. Inorganic and Organic Chemistry are two different branches of chemistry that depend on the nature of compounds. The main difference between organic and inorganic chemistry is that  inorganic chemistry is the study of inorganic compounds, whereas organic chemistry is the study of organic compounds.

This article explains,

1. What is Inorganic Chemistry?
     – Definition, Reactions, Structure, Properties

2. What is Organic Chemistry?
     – Definition, Reactions, Structure, Properties

3. What is the difference between Inorganic and Organic Chemistry?

What is Inorganic Chemistry

In general, inorganic molecules are molecules that do not have a definitive hydrocarbon (made of carbon and hydrogen atoms) structure. They are mainly composed of ions, and these ions act as the basis of their chemical reactivity. Ions are formed when a molecule or atom has either a less or an additional number of electrons than its original electronic configuration. However, ions are formed in order to make the atoms/molecules more stable, giving them the electronic configuration of a noble gas. Therefore, when atoms attain the noble gas electronic configuration, they become either positively or negatively charged. Positively charged species are called cations and negatively charged species are called anions. Cations and anions naturally get attracted to each other through ionic interactions forming the strongest types of chemical bonds, called ionic bonds. In general, they are all categorised as inorganic compounds. However, there is also a large number of compounds, bound by covalent bonds, which fall under the category of inorganic compounds. i.e. HCl, CO2, H2O

The main type of inorganic reactions are displacement reactions and redox reactions. What happens in the case of displacement reactions, is that the cations and anions between two compounds exchange depending on their reaction potential. On the other hand, redox reactions take place due to oxidations and reductions. Therefore, metals and their forms are quite significant in inorganic chemistry, including the branch of transition metal chemistry. Inorganic compounds generally have higher melting points. Other techniques such as recrystallization, electro chemistry, x-ray crystallography, acid-base chemistry, pH chemistry, catalysis etc. all deal with inorganic chemistry.

The structure of the ionic framework in potassium oxide

What is Organic Chemistry

Apart from organometallic compounds, (compounds that include an organic structure plus metals), there is very little overlap between organic chemistry and inorganic chemistry. As mentioned above, organic molecules are made of hydrocarbons. Therefore, it is very easy to distinguish between an organic and inorganic compound. Until the 19th century, it was believed that organic molecules were natural and can be only extracted from nature. However, the largest breakthrough in organic chemistry was when Kekule explained the existence of the structure of benzene. The benzene core has become an essential part of organic chemistry.

The classification and the reactions of organic compounds depend on their functional groups. The length of the carbon chain would simply define the physical characteristics of the compound. Organic compounds tend to melt and boil, unlike the inorganic compounds. Methods of spectroscopy are mainly used for the analysis of organic compounds. Organic chemistry is heavily used in medicinal chemistry for the discovery of new drugs, nutrition chemistry, flavor and fragrance chemistry, petroleum, etc.

Ball-and-stick model of the methane molecule

Difference Between Organic and Inorganic Chemistry

Definition

Inorganic chemistry deals with inorganic compounds, typically those that have an ionic base. 

Organic chemistry deals with organic compounds made of hydrocarbons.

Reactions

Inorganic chemistry includes acid-base reactions, displacement reactions, redox reactions etc.

Organic chemistry includes reactions that depend on the functional group present on the compound.

Structure

Inorganic chemistry mainly deals with salts and crystals.

Organic chemistry deals with oils, fats, sugars etc.

Physical Properties

Inorganic molecules have higher melting points and degrade instead of boiling.

Organic molecules melt and boil.

Image Courtesy:

“Methane-CRC-MW-3D-balls” By Ben Mills – Own work (Public Domain) via Commons Wikimedia

“Potassium-oxide-3D-vdW” (Public Domain) via Commons Wikimedia

About the Author: Melani Maria

Melani Maria has a BSc (Hons) degree in Chemistry and doing her Masters, specializing in Perfumery and Business. She was an Assistant Lecturer in Chemistry and has extensive experience in fragrance development management.