How to balance chemical equation?

While writing chemical equation, the reactants are on the left before arrow and the products on the right. The arrow ---> is there to show that the reaction is irreversible. It shows the direction of the reaction. The plus sign indicates that there is more than one reactant or product on each side of the equation.

A word equation provides a good summary but a symbol equation provides more detail. It shows more information and allows us to see how many atoms and molecules are involved in each reaction

Example-1:

$$\text{C}+\text{O}_2\;\rightarrow\text{CO}$$

Solution :

$$2\text{C}+\text{O}_2\;\rightarrow2\text{CO}$$

Example-2:

$$\text{Mg}_3\text{N}_2+\text{H}_2\text{o}\rightarrow\text{Mg}\left(\text{OH}\right)_2+\text{NH}_3$$

Solution :

$$\text{Mg}_3\text{N}_2+\text{H}_2\text{o}\rightarrow\text{Mg}\left(\text{OH}\right)_2+\text{NH}_3$$

Step-1: Check Metal (Mg).

$$\text{Mg}_3\text{N}_2+\text{H}_2\text{o}\rightarrow\;3\text{Mg}\left(\text{OH}\right)_2+\text{NH}_3$$

Step-2: Check Non-metal (N).

$$\text{Mg}_3\text{N}_2+\text{H}_2\text{o}\rightarrow3\text{Mg}\left(\text{OH}\right)_2+2\text{NH}_3$$

Step-3 :Check Oxygen.

$$\text{Mg}_3\text{N}_2+6\text{H}_2\text{o}\rightarrow3\text{Mg}\left(\text{OH}\right)_2+2\text{NH}_3$$

Balance Equation:

$$\text{Mg}_3\text{N}_2+6\text{H}_2\text{o}\rightarrow3\text{Mg}\left(\text{OH}\right)_2+2\text{NH}_3$$

Example-3:

$$\text{CuO}+\;\text{NH}_3\rightarrow\;\text{Cu}\;+\;\text{N}_2\;+\;\text{H}_2\text{O}$$

Solution :

$$\text{CuO}\;+\;\text{NH}_3\;\rightarrow\;\text{Cu}\;+\;\text{N}_2\;+\;\text{H}_2\text{O}$$

Step-1: Check Metal (Cu).

$$\text{CuO}+\text{NH}_3\rightarrow\text{Cu}+\text{N}_2+\text{H}_2\text{O}$$

So cu is already balanced.

Step-2: Check Non-metal (N).

$$\text{CuO}+\;2\text{NH}_3\rightarrow\text{Cu}+\text{N}_2+\text{H}_2\text{O}$$

Step-3: Check Oxygen.

$$\text{CuO}+2\text{NH}_3\rightarrow\text{Cu}+\;\text{N}_2+\text{H}_2\text{O}$$

Oxygen is already balanced.

Step-4: Check Hydrogen.

$$\text{CuO}+2\text{NH}_3\rightarrow\text{Cu}+\text{N}_2+3\text{H}_2\text{O}$$

Step-5: Check again start with metal, non-metal, hydrogen and oxygen.

$$3\text{CuO}+2\text{NH}_3\rightarrow\text{Cu}+\text{N}_2+3\text{H}_2\text{O}$$

Step-6: Check again start with metal, non-metal, hydrogen and oxygen.

$$3\text{CuO}+2\text{NH}_3\rightarrow3\text{Cu}+\text{N}_2+3\text{H}_2\text{O}$$

Balanced Equation :

$$3\text{CuO}+2\text{NH}_3\rightarrow3\text{Cu}+\text{N}_2+3\text{H}_2\text{O}$$