Question

Solid calcium carbonate is heated to produce solid calcium oxide and carbon dioxide gas is released

(a) Translate the following chemical change in the form of a chemical equation

(b) Make it informative

(c) Balance it if required

Answer 1

Any chemical change in the matter which involves transformation into one or more substances with entirely different properties is known as a chemical reaction.

Chemical reactions can be represented by chemical equations. The substances that take part in the chemical reaction are called reactants and the chemicals which are formed as a result of the reaction between reactants is known as product.

$\mathrm{X}+\mathrm{Y}\to \mathrm{P}$ in the given equation X and Y are reactants and P is the product.

Solid calcium carbonate is heated to produce solid calcium oxide and carbon dioxide gas is released.

a) In this reaction

Reactant = Calcium carbonate (${\mathrm{CaCO}}_3$)

Product = Calcium oxide ($\mathrm{CaO}$) and carbon dioxide (${\mathrm{CO}}_2$)

Chemical equation: ${\mathrm{CaCO}}_3\stackrel{∆}{\to }\mathrm{CaO}+{\mathrm{CO}}_2$

$∆$= it represents heating or decomposition.

b) Informative chemical equation:

The chemical equation can be made more informative by adding the following properties:

• Physical state of reactant and product
• Evolution of gas
• Precipitate formed
• Reaction conditions like temperature and pressure
• Evolution or absorption of heat during reaction

$\underset{\mathrm{calcium}\mathrm{carbonate}}{{\mathrm{CaCO}}_3\left(\mathrm{s}\right)}\stackrel{∆}{\to }\underset{\mathrm{calcium}\mathrm{oxide}}{\mathrm{CaO}\left(\mathrm{s}\right)}+\underset{\mathrm{carbon}\mathrm{dioxide}}{{\mathrm{CO}}_2}\uparrow$ Informative chemical equation

c) Balanced equation: The chemical equation in which the number of atoms of each element on the reactant side as well as the product side is equal is known as a balanced equation.

Balancing the following chemical equation:

$\underset{\mathrm{calcium}\mathrm{carbonate}}{{\mathrm{CaCO}}_3\left(\mathrm{s}\right)}\stackrel{∆}{\to }\underset{\mathrm{calcium}\mathrm{oxide}}{\mathrm{CaO}\left(\mathrm{s}\right)}+\underset{\mathrm{carbon}\mathrm{dioxide}}{{\mathrm{CO}}_2}\uparrow$

Steps to balance the chemical equation:

• Count the number of atoms of each element on either side. Now first balance the compound with the maximum number of atoms

A number of atoms of each element on the reactant side:

$\mathrm{Ca}=1,\mathrm{C}=1,\mathrm{O}=3$

A number of atoms of each element on the product side:

$\mathrm{Ca}=1,\mathrm{C}=1,\mathrm{O}=3$

The no. of atoms of calcium, carbon, and oxygen is equal on both the reactant and product side hence the equation is balanced.