Question

Balance the chemical equation ${\mathrm{N}}_2+{\mathrm{H}}_2\to {\mathrm{NH}}_3$

Answer 1

• Given the unbalanced chemical equation : ${\mathrm{N}}_2+{\mathrm{H}}_2\to {\mathrm{NH}}_3$
• Compare the total number of atoms of each element on the reactant side and the product side.

Element	Reactant side	Product side
Nitrogen($\mathrm{N}$)	2	1
Hydrogen($\mathrm{H}$)	2	3

• Now, stoichiometric coefficients are added to molecules containing an element that has a different number of atoms on the reactant side and the product side.
• The coefficient must balance the number of atoms on each side.
• In order to balance Hydrogen($\mathrm{H}$) multiply $2$on the product side and multiply 3 with hydrogen on the left-hand side.

Element	Reactant side	Product side
Nitrogen($\mathrm{N}$)	2	1 X 2
Hydrogen($\mathrm{H}$)	2 X 3	3 X 2

• Reaction becomes, ${\mathrm{N}}_2+3{\mathrm{H}}_2\to 2{\mathrm{NH}}_3$
• The number of atoms of the elements on the reactant and product side is equal.
• The overall balance equation, $\underset{\mathrm{Nitrogen}}{{\mathrm{N}}_2\left(\mathrm{g}\right)}+\underset{\mathrm{Hydrogen}}{3{\mathrm{H}}_2\left(\mathrm{g}\right)}\to \underset{\mathrm{Ammonia}}{2{\mathrm{NH}}_3\left(\mathrm{g}\right)}$
• Now, the above chemical equation is balanced.