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Chemical Formula of Common Compounds

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Chemical Formulas of compounds are symbolic representations of their chemical composition i.e. they tell us about which elements the chemical compound is made of and in what ratio. For example, the chemical formula of common salt is NaCl which tells us that it is made up of Sodium(Na) and Chlorine(Cl) in a 1:1 ratio. In this article, we will learn about the chemical formulae of some common compounds in detail.

What is Chemical Compound Formula?

A chemical formula is a representation of a substance’s molecular composition in terms of the symbols representing the components that make up the molecule. A molecular formula is another name for a chemical formula. 

An element’s or a compound’s chemical formula can be used. A chemical formula is a technique of presenting information on the chemical proportions of atoms that make up a chemical compound or molecule using chemical element symbols, numbers, and other symbols like parentheses, dashes, brackets, and commas.

Formulae(Symbols) of Elements

Chemical formula of an element is a description of the molecule’s composition, with the symbol indicating the element and the subscript indicating the number of atoms in one molecule. 

Since one molecule of hydrogen contains two hydrogen atoms, the formula for hydrogen is H2. One molecule of hydrogen element includes two hydrogen atoms, according to the formula H2. Also, 2H denotes two separate hydrogen atoms, H2 denotes one hydrogen molecule, and 2H2 denotes two hydrogen molecules. 

Similarly, oxygen’s molecular formula is O2, nitrogen’s molecular formula is N2, and chlorine’s molecular formula is Cl2. Since inert gases like helium, none, and argon are monoatomic, they have the same symbols. There are no unique equations for the metals; they are all represented by their symbols.

The following table lists the molecular formulas for some of the most common elements:

















Formulae of Compounds

Chemical formula of a compound represents the elements present in the substance’s molecule in terms of their symbols. In other words, the formula of a compound tells us “the kind of atoms” present in one molecule of the compound, as well as the number of atoms of various elements present. 

A compound’s chemical formula is a description of its composition in which the chemical symbols indicate which elements are present and the subscripts indicate how many atoms of each element are present in one molecule. A compound’s chemical formula is a symbolic representation of the compound’s chemical composition. A chemical formula gives information about the elements that make up a compound’s molecules, as well as the ratio in which these elements’ atoms combine to form those molecules. 

Chemical formulae provide insight and distinction into a compound’s chemical composition. They also show the proportions in which the various constituents combine to generate the desired combination. While representing a compound in a chemical equation, its chemical formula is important. Ions, free radicals, and other chemical species can all be represented using chemical formulas. Most elements have only their chemical symbol as their formula. In balanced chemical equations, a chemical formula is used to represent an element or compound.

Chemical formulas and elements found in several common molecular compounds are listed below.



Elements present

Carbon dioxide


C and O



H and O

Sulphur dioxide


S and O



N and H

Hydrogen chloride


H and Cl



C and H



C, H, and O

Hydrogen sulphide


H and S

Types of Chemical Formulae

There are various types of chemical formulae and all the chemical formulae represent different attribute of the chemical compound. In general the chemical formula represent the molecular formula of the compound that is the representation of the molecule of the compound. There are three general types of chemical formulae that are,

  • Molecular Formula
  • Emperical Formula
  • Structural Formula

Now let’s learn about them in detail.

Molecular Formula

The molecular formula of any compound represent the molecule of the compound and it tells us that how many atoms and in which ratio they are combined to form that compound. The molecular formula of Glucose is C6H12O6 it tells us that in forming a glucose molecule we require 6 carbon atoms, 12 hydrogen atoms and 6 oxygen atoms.

Emperical Formula

The empirical formula of any compound tells us that how many atoms are required to a compound. It also tells us the ratio in which the atoms combine to form the compounds. For example the empirical formula for glucose is CH2O this tells us that in forming glucose we need carbon, hydrogen and oxygen atom in 1:2:1 ratio.

Structural Formula

The structural formula of any compound tells us the exact structure of the compound its tell us which atom forms bond with which atom in forming the compound.

Importance of Chemical Formulae of Compounds

The importance of Chemical Formulae of Compounds can be understood as,

  • Compound’s name is represented by a formula.
  • Names of all the elements in the molecule are given in formulae.
  • Number of atoms of each element contained in a molecule is given by formulae.
  • One molecule of a compound is represented by a formula.
  • Formulae denote a definite mass of a substance.

List of Some Common chemical Compounds

The list of some common chemical compound of chemistry are tabulated below with their properties and general uses.

Common Name Chemical Formula Chemical Name General Uses
Baking Soda NaHCO3 Sodium Bicarbonate It is used for baking purposes.
Bleaching Powder CaOCl2 Calcium Oxychloride It is used as a disinfectant and as a bleaching agent.
Blue Vitriol CuSO4.xH2O Copper Sulphate It is used for fungus control.
Borax Na2[B4O5(OH)4].8H2O Sodium Borate It is used for manufacturing detergent.
Carbolic Acid C6H5OH Phenol It is used as a home cleaner and disinfectant.
Caustic Potash KOH Potassium Hydroxide It is used in the manufacturing of fertilizers and soaps
Chloroform CHCl3 Trichloro methane It is used as a solvent and is used in manufacturing floor polish.
Common Salt NaCl Sodium Chloride It is used for flavouring and preserving food.
Dry Ice CO2 Solid Carbon Dioxide It is used as a food preservative.
Galena PbS Lead(II) Sulphide It is used in pottery.
Green Vitriol FeSO4.7H2O Ferrous Sulphate Heptahydrate It is used in the treatment of sewage water
Gypsum CuSO4.2H2O Calcium Sulphate dihydrate It is used in home manufacturing.
Heavy Water D2O Deuterium Oxide It is used as a moderator in nuclear reactors.
Laughing Gas N2O Nitrous Oxide It is used by dentists.
Quick lime CaO Calcium Oxide It is used in iron and steel manufacturing.
Slacked lime Ca(OH)2 Calcium Hydroxide It is used in plaster and mortar
Lime Stone CaCO3 Calcium Carbonate It is used as marble
Caustic Soda NaOH Sodium Hydroxide It is used in the manufacturing of paper, aluminium and other.
Marsh Gas CH4 Methane It is a poisonous gas which is mainly found in mines. 
Milk of Magnesia Mg(OH)2 Magnesium Hydroxide It is used as an antacid.
Spirit of Niter HNO3 Nitric Acid It is used in the production of fertilizers and explosives.
Muriatic Acid HCl Hydrochloric Acid It is used in food and leather processing.
Oil of Vitriol H2SO4 Sulphuric Acid It is used in the manufacturing of fertilizers.
Plaster of Paris CaSO4.1/2H2O Calcium Sulphate Hemihydrate It is used as a protective coating for walls.
Quick Silver Hg Mercury It is used in barometers and clinical thermometers.

Also, Read

FAQs on Chemical Compounds Formulas

1. What are Chemical Formula of Compound?

The chemical formula of any compound represents the atoms and their ratio that are used to form a compound. For example the chemical compound for carbon dioxide is CO2 that tells us that in forming a carbon dioxide we need one carbon molecule that is attached with two oxygen molecules.

2. What is Difference between O2 and 2O?

O2 indicates that one molecule of oxygen element contains 2 atoms of oxygen and 2O indicates two separate atoms of oxygen.

3. What is Chemical Formula of Sodium Chloride?

The chemical formula for Sodium Chloride is NaCl. It is also called common salt.

4. What is Chemical Formula of Bleaching Powder?

The chemical formula for Bleaching Powder is CaOCl2

5. What is an Atom?

The smallest unit of the matter that participate in a chemical reaction are called atoms. Atoms are believed to be indestructible but modern science has prove that atoms are further divided into smaller parts. Atoms combined in different ratios to form the molecules.

6. What is a Molecule?

The group of ayoms that represent the physical and chemical properties of a compound are called the molecule. A molecule represent the smallest unit that is replicated to form the whole compound.

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Last Updated : 22 Sep, 2023
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