Question

Ammonia, NH3(g), can be used as a substitute for fossil fuels in some internal combustion

engines. The reaction between ammonia and oxygen in an engine is represented by
the unbalanced equation below.
NH3(g) + O₂(g) →→ N₂(g) + H₂O(g) + energy
6. Balance the equation in the space below for the reaction of ammonia and oxygen, using the
smallest whole-number coefficients.

Answer 1

4 NH₃ (g) + 3 O₂ (g) ----> 2 N₂ (g) + 6 H₂O (g) + energy

Step-by-step explanation:

The unbalanced equation:

NH₃ (g) + O₂ (g) ----> N₂ (g) + H₂O (g) + energy

Reactants: 1 nitrogen, 3 hydrogen, 2 oxygen

Products: 2 nitrogen, 2 hydrogen, 1 oxygen

The sort-of balanced equation

2 NH₃ (g) + 1/2 O₂ (g) ----> N₂ (g) + 3 H₂O (g) + energy

I first started by balancing the nitrogens. This then lead me to balance the hydrogens. When I went to balance the oxygens, only a 1/2 coefficient would work. However, 1/2 coefficients are technically incorrect. To get rid of this coefficient, you need to multiply each coefficient by 2.

The balanced equation:

4 NH₃ (g) + 3 O₂ (g) ----> 2 N₂ (g) + 6 H₂O (g) + energy

Reactants: 4 nitrogen, 12 hydrogen, 6 oxygen

Products: 4 nitrogen, 12 hydrogen, 6 oxygen

Now, all of the elements are equal on both sides and there are no 1/2 coefficients. These are the smallest whole-number coefficients because some of the numbers cannot be further simplified (3).