Question

How do you balance the equation:
$N{{H}_{3}}+{{O}_{2}}\to N{{O}_{2}}+{{H}_{2}}O$

Answer 1

Hint This reaction is the formation of nitrogen dioxide from ammonia. To balance the equation, first balance the nitrogen atoms and then balance the hydrogen and oxygen atoms.

Complete step by step answer:
The reaction given in the question is the formation of nitrogen dioxide from ammonia when ammonia reacts with oxygen it forms nitrogen dioxide and water. Now, for balancing this reaction first we have to balance the elements in the reactions other than hydrogen and oxygen atoms. In this reaction only nitrogen is there other than hydrogen and oxygen. First, we have to balance the number of nitrogen atoms. The reaction is:
$N{{H}_{3}}+{{O}_{2}}\to N{{O}_{2}}+{{H}_{2}}O$
So, in this reaction, the number of nitrogen is the same on both sides, i.e., one nitrogen atom is present in the reactant and product side. Therefore, there is no need to change the reaction.
Now, balancing the hydrogen atoms in the reaction, the hydrogen atoms in the reactant side is 3 and on the product side, the number of hydrogen atoms is 2. So, multiplying the ammonia with 2 and water with, we get:
$2N{{H}_{3}}+{{O}_{2}}\to N{{O}_{2}}+3{{H}_{2}}O$
Now, on the reactant side, the nitrogen is 2 and on the product side, the nitrogen atom is 1. So, multiplying the nitrogen dioxide with 2, we get:
$2N{{H}_{3}}+{{O}_{2}}\to 2N{{O}_{2}}+3{{H}_{2}}O$
Now, balancing the oxygen atoms in the reaction, the oxygen atoms on the reactant side is 2 and the number of oxygen atoms on the product side is 7. So, multiplying the oxygen in the reactant with 7 and multiplying both the products with 2, we get:
$2N{{H}_{3}}+7{{O}_{2}}\to 4N{{O}_{2}}+6{{H}_{2}}O$
To finally balance this equation, multiply 2 with $2N{{H}_{3}}$:
$4N{{H}_{3}}+7{{O}_{2}}\to 4N{{O}_{2}}+6{{H}_{2}}O$

Note: It must be noted that first balance all the elements other than O and H, and after balancing hydrogen, check all the other atoms are balanced then only proceed for the balancing of the oxygen atoms.