Question

Balance the following equations.
$\mathrm{Fe}+{\mathrm{O}}_2\to {\mathrm{Fe}}_2{\mathrm{O}}_3$

Answer 1

Balanced chemical equation -

• A chemical equation is said to be balanced if the number of atoms of each element on the left-hand side is equal to the number of atoms present on the right-hand side.
• In order to balance a chemical equation, it is required to know what are reactants that are taking part in a chemical reaction and what are products will be formed.

Balancing a chemical equation-

Using Hit by trial method

$\mathrm{Fe}+{\mathrm{O}}_2\to {\mathrm{Fe}}_2{\mathrm{O}}_3$

Elements	Number of atoms on reactant side	Number of atoms on product side
Fe	1	2
O	2	3

1. To balance Fe, put coefficient 2 on the left-hand side. $2\mathrm{Fe}+{\mathrm{O}}_2\to {\mathrm{Fe}}_2{\mathrm{O}}_3$
2. On doing the above step, to balance the O, multiply left side by 3 and right side by 2. $2\mathrm{Fe}+3{\mathrm{O}}_2\to 2{\mathrm{Fe}}_2{\mathrm{O}}_3$
3. Now again balance Fe, by putting coefficient 4 on the left-hand side. $4\mathrm{Fe}+3{\mathrm{O}}_2\to 2{\mathrm{Fe}}_2{\mathrm{O}}_3$
4. Hence, the balanced chemical equation is $4\mathrm{Fe}+3{\mathrm{O}}_2\to 2{\mathrm{Fe}}_2{\mathrm{O}}_3$