Chemical Compound

Last Updated : 18 Apr, 2024

Chemical Compounds in chemistry are pure form of matter which are formed by combination of two or more elements in a fixed ratio. They are different from the mixture in which the constituent particles are combined in any ratio. For example, sugar solution is a mixture but water is a chemical compound. This is because in sugar solution water and sugar can combine in any ratio to form solution but to form water i.e. H2O, hydrogen and oxygen have to always combine in fix ratio i.e. 2:1.

In this article, we will learn in detail about what is chemical compounds, their example, types, bonding, some of commonly used chemical compound and how are they different from molecules and elements.

Table of Content

What are Chemical Compounds?

When two or more elements chemically combine in a fixed ratio by mass, the resulting product is known as a compound. These compounds exhibit unique properties that are different from those of their constituent elements. In these chemical compounds, the atoms are held together with chemical bonds, which can be either ionic or covalent, depending on the type of compound. All the matter in the universe is composed of the atoms of more than 100 different chemical elements, which are found both in pure form and combined in chemical compounds.

Chemical compounds can have a wide range of properties, including color, odor, melting point, boiling point, solubility, and reactivity.
They can be found in various forms, including solids, liquids, and gases, and these play a crucial role in the day to day life.
Chemical compounds follow the law of definite proportions, also known as the law of constant composition.
This law states that a chemical compound always contains the same elements in the same proportion by mass, regardless of the source or method of preparation.

Example of Chemical Compound

Water is H₂O which shows two atoms of hydrogen and one atom of oxygen have combined to form one molecule of H₂O. This H₂O is a compound. To form water hydrogen and oxygen will always have to combine in 2:1.

Similarly, Common salt is NaCl, which shows one atom of sodium and one atom of chlorine combine to form one molecule of NaCl.

History of Chemical Compound

The collisional pressure eventually led a few helium atoms to share their electrons with protons. Thus, the first chemical bonds were formed. The new compound of helium and hydrogen was called Helium hydride or helonium (HeH⁺), the very first molecule (of any sustained abundance) in the universe.

The term "compound" with a meaning similar to the modern understanding has been used at least since 1661 when Robert Boyle's book The Sceptical Chymist was published. In this book, Boyle variously used the terms "compound", "compounded body", "perfectly mixt body", and "concrete".

Types of Chemical Compound

Chemical compounds can be broadly categorized into several types based on their composition and bonding characteristics. They are:

Chemical compounds	Definition	Examples
Ionic Compounds	These compounds are formed by the transfer of electrons from one atom to another, which result in the formation of positively and negatively charged ions.	Sodium chloride (NaCl) Calcium carbonate (CaCO₃).
Covalent Compound	These compounds are formed by the sharing of electrons between two different or same atoms. These compounds mostly consist of nonmetals.	Water (H₂O) Methane (CH₄)
Organic Compounds	These compounds contain carbon atoms bonded to hydrogen atoms, along with other elements such as oxygen, nitrogen, sulfur, and halogens. These compounds are essential to life.	Carbohydrates, proteins, lipids, and nucleic acids.
Inorganic Compounds	These compounds typically lack carbon-hydrogen (C-H) bonds.	salts, metals, minerals, and simple oxides.
Metallic Compounds	These compounds are characterized by the presence of metal atoms held together by metallic bonds. They often have high thermal and electrical conductivity	Alloys such as brass (copper and zinc) and steel (iron and carbon)
Acids and Bases	Acids are compounds that release hydrogen ions (H+) in solution, while bases are compounds that release hydroxide ions (OH-) in solution.	Hydrochloric acid (HCl) Sodium hydroxide (NaOH)
Coordination Compounds	Any of a class of substances with chemical structures in which a central metal atom is surrounded by nonmetal atoms or groups of atoms, called ligands, joined to it by chemical bonds.	Vitamin B₁₂, Hemoglobin, Chlorophyll, Dyes, Pigments and Catalysts
Hydrates	These compounds contain water molecules that are loosely bound to the main compound through hydrogen bonds	copper sulfate pentahydrate (CuSO₄·5H₂O)
Organometallic Compounds	These compounds contain at least one metal to carbon atom in which carbon is part of an organic group.	Grignard Reagent Triethylborane
Polymeric Compounds	These compounds are composed of repeating structural units called monomers.	Plastics, rubbers, and some types of fibers.

Bonding in Chemical Compounds

The formation of a chemical bond between two or more atoms, molecules or ions to give rise to a chemical compound. These chemical bonds keep the atoms together in the results in the formation of the compound. The most common types of chemical bonding are:

Ionic Bonding

Ionic bond is formed when one or more electrons are transferred from one atom to another, resulting in the formation between a positively charged ions (cations) and negatively charged ions (anions) is called an ionic bond. Example: sodium chloride (NaCl), where sodium (Na) donates an electron to chlorine (Cl) to form Na⁺ and Cl^- ions.

Covalent Bonding

Covalent bonding involves the sharing of electron pairs between atoms to become a stable electron configuration. In a covalent bond, atoms share one or more pairs of electrons, results in the formation of molecules. Examples: Water (H2O), where Oxygen (O) shares electrons with two Hydrogen (H) atoms.

Metallic Bonding

Metallic bonding occurs in metals and alloys, Where positively charged metal ions are held together. These electrons are free to move throughout the material, contributing to its electrical conductivity. Examples: Pure metals like Copper (Cu) and alloys like bronze (composed of copper and tin).

Hydrogen Bonding

Hydrogen Bond is a type of polar covalent bonding between oxygen and hydrogen, wherein the hydrogen develops a partial positive charge. This implies that the electrons are pulled closer to the more electronegative atoms like oxygen atom. Hydrogen bonds are relatively weak compared to covalent or ionic bonds.