Question

Translate the following statements into chemical equations and balance them:
Hydrogen gas combines with nitrogen to form ammonia
A: $3{{\text{H}}_2}(g) + {{\text{N}}_2}(g) \to {\text{2N}}{{\text{H}}_3}(g)$
B: ${{\text{H}}_2}(g) + {{\text{N}}_2}(g) \to {\text{N}}{{\text{H}}_3}(g)$
C: ${\text{2}}{{\text{H}}_2}(g) + {{\text{N}}_2}(g) \to 3{\text{N}}{{\text{H}}_3}(g)$
D: ${{\text{H}}_2}(g) + {{\text{N}}_2}(g) \to {\text{2N}}{{\text{H}}_3}(g)$

Answer 1

For a complete reaction the number of atoms of each element in a reaction should be the same on both sides of the reaction and balancing should be done keeping in mind that charges also remain same on either side of reaction.

Complete answer:
Hydrogen gas$({H_2})$ reacts with nitrogen gas$({N_2})$ to give ammonia $(N{H_3})$that means;
${H_2} + {N_2} \to N{H_3}$
But, in this reaction the number of atoms of both Nitrogen and hydrogen are not balanced on either side of reaction
As there are 2 hydrogen and 2 nitrogen atoms on the reactant side of the reaction where as there is 3 hydrogen atoms while there is only 1 nitrogen atoms ,so, obviously the reaction is not balanced
Now, writing the balanced reaction,
$3{H_2} + {N_2} \to 2N{H_3}{\text{ }} \to {\text{equation 1}}$
Here, in equation 1 ,there are 6 hydrogen atoms and 2 nitrogen atoms on the reactant side and also 2 nitrogen and 6 hydrogen on the product side,hence we can conclude that the reaction is balanced.

Option A is the correct answer.

Additional Information:
The formation of ammonia takes place using hydrogen gas and nitrogen gas in industries via Haber’s process.
The productivity of Haber’s process can be enhanced by using Iron which helps to achieve acceptable yield in given time.
Lower temperature favours formation of ammonia.

Note:

1. For a balanced reaction the charges on the reactant side as well as the product side must be balanced.
2. In a redox reaction the charges are taken into factor considering the valence of the elements ,like in this case charge of hydrogen in hydrogen gas is 0 , charge of nitrogen in nitrogen gas is 0 and charge on hydrogen atom in ammonia is +1 while the charge on nitrogen in ammonia is -3.