Answer:
Option B. 4NH3(g) + 5O2(g) —> 4NO(g) + 6H2O(g)
Explanation:
The reaction between ammonia, NH3 and oxygen, O2, will produce nitric oxide and water as shown below:
NH3(g) + O2(g) —> NO(g) + H2O(g)
Now, let us balance the equation.
This is illustrated below:
NH3(g) + O2(g) —> NO(g) + H2O(g)
There are 3 atoms of H on the left side and 2 atoms on the right side. It can be balance by putting 4 in front of NH3 and 6 in front of H2O as shown below:
4NH3(g) + O2(g) —> NO(g) + 6H2O(g)
There are 4 atoms of N on the left side and 1 atom on the right side. It can be balance by putting 4 in front of NO as shown below:
4NH3(g) + O2(g) —> 4NO(g) + 6H2O(g)
Now, the are 2 atoms of O on the left side and a total of 10 atoms on the right side. It can be balance by putting 5 in front of O2 as shown below:
4NH3(g) + 5O2(g) —> 4NO(g) + 6H2O(g)
Now, we can see that the equation is balanced.
Therefore, option B gives the balanced chemical equation for the reaction.