Question

When potassium nitrate is heated, it decomposes into potassium nitrite and oxygen. Write a balanced equation for this reaction and add the state symbols of the reactants and products.

Answer 1

Hint: A chemical equation shows the starting compound also known as reactant on the left hand side of the reaction and the final compound also known as the products on the right hand side of the reaction.

Complete Solution :
Potassium nitrate also known as saltpetre. The molecular formulae of potassium nitrate is$KN{O}_3$ . It is an ionic salt where the cation is potassium ion and the anion is nitrate ion. When potassium nitrate is heated it decomposes into potassium nitrate and oxygen.
Symbol of potassium nitrate is: $KN{O}_3$
Symbol of oxygen is: $O$
Symbol of potassium nitrite is: $KN{O}_2$
The reaction involves is:
$$KN{O}_3(s)\to KN{O}_2(s)+O_2(g)$$

- A chemical equation is balanced when the number of atoms present at the reactant side is equal to the number of atoms present at the product side. Hence, a balanced chemical reaction will be:
$$2KN{O}_3(s)\to 2KN{O}_2(s)+O_2(g)$$

Additional information-
To write the chemical reaction we should first understand its participants:
The elements are represented by their symbol.
The reactants also known as the substrates are written on the left-hand side of the chemical reaction and the products also known as the output of the chemical reaction are written on the right-hand side of the chemical reaction.
An arrow is used to represent the direction in which the chemical reaction flows.

Note: While writing a chemical equation many symbols are used. Similarly, to describe the physical state of the reacting entities during the course of reaction many symbols are used i.e. The symbol (s) is used for solid- state. The symbol (l) is used to denote the liquid state. The symbol (g) is used to denote the gaseous state. The symbol (aq) is used to denote the aqueous solution.