Chemical Formula: Types & Importance

A chemical formula indicates the number of atoms of a specific element, or of multiple elements, in a chemical compound. 

• The numerical values indicated as subscripts on specific symbols within the formula indicate the number of each specific atom in the chemical substance.
• A chemical formula for water, for instance, H₂O, where a molecule of water is composed of two atoms of hydrogen and one atom of oxygen.

Key Terms: Chemical Formula, Molecular, Structural, Empirical, Glucose, Chemical Compound

---

What is Chemical Formula? 

[Click Here for Sample Questions]

Chemical formulas are any of a variety of statements that explain the make-up or physical shape of chemical compounds. Chemical symbols are used in chemical formulas to identify each constituent part, along with the relative amount of atoms that make up each element.

• Information about a compound's chemical make-up may be found in its chemical formula. 
• They also show how the basic parts of the compound join in what proportions.
• While representing a compound in a chemical equation, the chemical formula of the compound is essential.
• Aside from ions, free radicals, and other chemical species, chemical equations can also be used to represent them.
• A compound is an object composed of two or more components in a predetermined ratio. 
• We can determine the number of atoms in a substance by looking at its chemical formula.
• It includes the symbols for the atoms of each element that is present in the compound as well as a count of how many of each element there are overall.

Read More: Ionic Radius

---

Types of Chemical Formula 

[Click Here for Previous Year Questions]

Chemical formulas can be of three different kinds:

1. Molecular Formula

 

The precise amount of atoms of each element contained in a molecule is given to us by the molecular formula, sometimes referred to as the true formula.

 

• Chemical symbols are followed by numerical subscripts, which represent the total number of atoms in each compound. 
• The sort of atoms contained in a compound's molecules is also disclosed by the molecular formula. 
• For instance, glucose has the chemical formula C₆H₁₂O₆.
• It shows how many carbon, hydrogen, and oxygen atoms are actually present in a single glucose molecule.

2. Empirical formula 

When anything is described as empirical, it may be evaluated by observation. 

• As a result, the simplest ratio of all the atoms present in the components that make up a compound is specified as the empirical formula.
• It is frequently derived from experimental data. 
• An illustration of an empirical formula derived from the glucose molecular formula.
• Glucose's empirical formula is CH₂O.
• It indicates the total number of C, H, and O atoms in the mixture.

3. Structural Formula

The locations of chemical bonds that connect a molecule's atoms are indicated by its structural formulae. 

• One, two, or three lines, representing single, double, or triple bonds, respectively, separate the symbols for the atoms in a structural formula from one other.
• The atomic bonding and spatial arrangement of the atoms are revealed by the structural formula. 
• It aids in separating apart the atoms that are and are not bound to one another. 8

Ethyl Acetate

Read More: F-block Elements

---

How to Write Chemical Formulas?

[Click Here for Sample Questions]

The names of the components of a compound, coupled with a few fundamental laws and written backwards, can be used to create a chemical formula.

• Valency may be used to write the chemical formula of binary compounds, which are formed of two separate elements.
• Valency is the ability of an elemental combination to create a compound or compounds. 
• Determine the valencies of the two items first
• Then identify the lowest common multiple of the two valencies to bring the sums of the valencies of the two separate elements into balance. 
• An atom having a positive charge is a cation, whereas an atom with a negative charge is an anion. 
• The metal should be put first in the formula if both a metal and a non-metal are present. 
• As in NaCl, where Na has a positive charge and Cl a negative one.

Read More: Atomic Radius

---

Importancе of Chеmical Formula

[Click Here for Previous Year Questions]

Thе chemical formula is of grеat importance in thе field of chemistry for sеvеral rеasons:

• Chemical formulas sеrvе as a unique idеntifiеr for compounds.
• Thеy providе a standardised and concisе representation of the elements and thеir proportions prеsеnt in a compound.
• Chеmical formulas reveal thе elemental composition of a compound and thе ratio in which thе atoms arе combinеd.
• Chemical formulas providе insights into thе propеrtiеs of compounds.
• Thеy help predict thе rеactivity, bonding, polarity, solubility, and othеr physical and chеmical propеrtiеs of substancеs.
• Chemical formulas arе used in thе nomenclature and classification of compounds. 
• Different naming conventions arе employed basеd on thе typе of compound, and thе formula plays a kеy rolе in assigning thе appropriatе namе. 

Read More:

---

Things to Remember 

• The chemical formula of a material is crucial when describing it in a chemical equation.
• The chemical formula of a substance is a symbolic representation of its chemical structure. 
• They also reflect the ratios in which the component elements combine to form the composite.
• Chemical formulas provide details about a compound's chemical composition.
• Chemical formulae can also be used to represent ions, free radicals, and other chemical entities.
• A specific chemical substance that comprises atoms from at least two different elements is referred to as a chemical compound.
• If more than one of the same kind of polyatomic ion exists, brackets are followed by a subscript when enclosing them in chemical formulations.
• The lowest whole-number ratio of the components in a compound is revealed by the empirical formula. 
• The actual number of atoms is not indicated by the empirical formula.

---

Previous Year Questions

1. Osmotic pressure can be increased by...[KCET 2016]
2. Pure line breed refers to...[AIIMS 2007]
3. Offsets are produced by...[NEET UG 2018]
4. Calculate the molarity of a solution containing 5g of NaOH in 450 mL solution...[CUET (UG) 2022]
5. For the circuit shown in the figure...[JEE Advanced 2009]
6. Curie temperature is the temperature above which...[AIEEE 2003]
7. The combination of gates shown below yields...[AIEEE 2010]
8. A couple produces...[NEET UG 1997]
9. Syngamy can occur outside the body of the organism in...[NEET UG 2013]
10. The potential of a hydrogen electrode at pH=10 is...[WBJEE 2010]