Balance the following equation: NH3 + O2→ NO + H2O
The correct answer and explanation is:
Balanced Chemical Equation:
4 NH₃ + 3 O₂ → 4 NO + 6 H₂O
Explanation:
To balance a chemical equation, the number of atoms of each element on the reactant side must equal the number on the product side. This follows the Law of Conservation of Mass, which states that matter is neither created nor destroyed in a chemical reaction.
The unbalanced equation is:
NH₃ + O₂ → NO + H₂O
Start with nitrogen (N). Each molecule of NH₃ has 1 nitrogen atom, and each NO molecule on the product side also contains 1 nitrogen atom. Begin by placing a 4 in front of NH₃ and NO:
4 NH₃ + O₂ → 4 NO + H₂O
Now, balance hydrogen (H). Each NH₃ molecule has 3 hydrogen atoms, so 4 NH₃ molecules provide 12 hydrogen atoms. These hydrogen atoms appear in H₂O on the product side. Each H₂O has 2 hydrogen atoms, so 6 H₂O molecules are needed to give 12 hydrogen atoms:
4 NH₃ + O₂ → 4 NO + 6 H₂O
Next, balance oxygen (O). On the product side, there are 4 oxygen atoms from 4 NO and 6 oxygen atoms from 6 H₂O, giving a total of 10 oxygen atoms. O₂ is the oxygen source on the reactant side, and each O₂ molecule has 2 oxygen atoms. To get 10 oxygen atoms, 5 O₂ molecules are needed:
4 NH₃ + 5 O₂ → 4 NO + 6 H₂O
However, this leads to an imbalance. There must have been a mistake in the oxygen count. Re-examine it.
From 4 NO: 4 O atoms
From 6 H₂O: 6 O atoms
Total: 4 + 6 = 10 O atoms
So, use 5 O₂ molecules to get 10 O atoms:
4 NH₃ + 5 O₂ → 4 NO + 6 H₂O
Now all elements are balanced:
- N: 4 on each side
- H: 12 on each side
- O: 10 on each side
The balanced equation is:
4 NH₃ + 5 O₂ → 4 NO + 6 H₂O