CBSE Class 10 Chemistry Notes: How To Make Chemical Formula Of Compounds?

The chemical formula of a compound reflects a substance’s chemical composition.

The chemical formula for compounds NCERT Solutions for Class 10 Science was introduced to describe the structure of compounds and molecules in a concise and abbreviated manner. These chemical formulas require only a basic comprehension of the chemistry language for reading and writing. Using these chemical formulas helps in creating chemical equations.

What Exactly is a Chemical Formula?

The chemical formula of a compound NCERT Solutions for Class 10 Science is used to identify the total number of elements that comprise the compound as well as the total number of atoms of each element in that chemical compound number, whether present in a molecule or a formula unit.

Having well-defined names of the elements NCERT Solutions for Class 10 Science and basic guidelines enable to name simple chemical compounds in a chemical formula. Thus, a compound name helps to write down the chemical formulas of the compounds.

Before moving further, it’s important to know certain terminologies used in the chemical formulas of compounds. Let’s get into it!

Terminology Definitions

Technical precision is essentially required to communicate in Science language. These definitions will be used in writing the chemical formula for various compounds.

Atoms: Atoms NCERT Solutions for Class 10 Science can be defined as the smallest and unbreakable particles that make up an element. They retain the element’s unique properties. An atom is made up of three primary sub-particles:

• Protons (positively charged particles)
• Neutrons (particles without any charge)

Protons and neutrons combine to form an atom’s nucleus or the centre.

• Electrons (negatively charged particles)

These little electrons move around the nucleus. They are crucial in the formation of compounds.

Elements: Elements NCERT Solutions for Class 10 Science are composed of only one type of atom (with more than two units of the same atoms). Metals, nonmetals, and semimetals are all examples of elements.

Also See: Difference between metals and non-metals

Molecule: Molecules represent the smallest fraction of a compound. A molecule holds the characteristics of the compound. A molecule is neutral; they are neither positively nor negatively charged.

Compounds: Compounds NCERT Solutions for Class 10 Science are formed when the atoms of an element mix together with the help of chemical bonds. Thus a chemical compound combines chemically. There are majorly two types of compounds based on the bonds, ionic and covalent compounds. Ionic compounds are typically formed when metals react with nonmetals. At the same time, covalent compounds are typically formed when nonmetals mix.

Ions: An ion is made when an atom or group of atoms acquires or releases one or more electrons, resulting in an increase or decrease of negatively or positively charged particles in the atom’s nucleus. When electrons are released, positive ions are formed. Similarly, when an electron is added, negative ions arise.

Element Symbol

Each element is represented with its unique symbol NCERT Solutions for Class 10 Science. The elements are depicted with their name and symbol in the periodic table of elements. These elements are symbolised with their initial first two letters (sometimes only the first letter, for example, H, for hydrogen). However, some elements have been known for a long period, and their symbols are derived from Latin or Greek names. For example, the sign for lead, Pb, is derived from the Latin word Plumbum.

Chemical Symbol

The element symbol is represented by the first two initial letters of the elements. The first letter is capitalized while writing the chemical symbol, and the second letter is always written in lowercase. The universal applicability of this standard format has minimized the confusion in learning chemistry. The symbol Bi, for example, represents bismuth, element 83. Similarly, the symbol BI refers to a compound consisting of boron (B, element 5) and iodine (I, element 53) NCERT Solutions for Class 10 Science.

Chemical Equation Writing and Balancing

A chemical equation can be defined by NCERT Solutions for Class 10 Science as a written statement describing the changes in chemical reactions by using chemical symbols and chemical formulas rather than chemical names.

The following example compares a chemical name explanation of a chemical reaction with a chemical equation for the same process.

• Chemical name description: Calcium sulphide interacts with water to generate calcium oxide and hydrogen sulphide.

• Chemical equation description: CaS + H2O → CaO + H2S

Curiously Enough: Chemical equations NCERT Solutions for Class 10 Science can be regarded as sentences of chemical language in the same way chemical symbols are regarded as letters of the language and formulae are thought of as words of the language.

Reactants NCERT Solutions for Class 10 Science can be referred to as the substances present at the beginning of a chemical reaction. A reactant is an initial substance in a chemical reaction that changes during the process. As the chemical reaction takes place, the reactants in the process are utilised, and new materials with new chemical properties are established, known as a new chemical product. The new substance created due to a chemical reaction is referred to as a product.

Techniques used in Writing Chemical Equations

These equations can be written using four techniques.

1. The chemical formula of the reactant is always presented on the left side of the chemical equation.

CaS + H2O → CaO + H2S

2. The new product generated after the chemical reaction process is always written on the right side of the chemical equation.

CaS + H2O → CaO + H2S

3. The arrow points out the new product formed after the chemical reaction process. The arrow distinguishes between the reactants and products.

CaS + H2O → CaO + H2S

The arrow denotes “to produce.”

4. The plus signs used between the chemical reactions distinguish the reactants from the products.

CaS + H2O → CaO + H2S

The plus signs on the reactant side (left side of the equation) denote “reacts with,” while plus signs on the product side (right side of the equation) denote “and.”

Writing Chemical Formula of Binary Compounds using Valency

A chemical formula specifies the ratios of the various elements in the chemical compound by density.

A binary compound can be defined as NCERT Solutions for Class 10 Science as a compound of only two different elements. Valencies are used to write the chemical equation of a binary compound because both the atoms in the compound must shed, acquire, or receive the same amount of electrons.

Writing a binary compound’s chemical formula requires:

• Evaluating the valencies of the atoms of the two elements.
• The sums of the valencies of the two elements should be equal to one in the chemical formula by calculating the lowest common factor of the two valencies.
• In the case of metal compounds, they should always come first in the formula.

Summary

A chemical formula NCERT Solutions for Class 10 Science is essentially a shortcut for representing the number and type of atoms in a chemical compound or molecule. To write chemical formulas, students should become familiar with chemical symbols, which they may find in their class 10 Science NCERT textbooks NCERT Solutions for Class 10 Science in the periodic table of elements section. The periodic table contains the entire names of all known elements and their symbols, such as H for hydrogen or Cl for chlorine. To excel at writing chemical formulas, students should grasp the chemical symbols, their valencies, etc. After that, they are ready to write the chemical formulas for the compounds!