Panel 3: Balancing by inspection
Unbalanced equation:
| NH3 |
+ |
O2 |
 |
NO |
+ |
H2O |
| Ammonia |
and |
oxygen |
yield |
nitric oxide |
and |
water. |
Step 1: balance nitrogen atoms
After noting that nitrogen appears in only one reactant
molecule, NH3, and one product molecule, NO,
balance the nitrogen atoms.
NH3 + O2
NO + H2O
Step 2: balance hydrogen atoms
Since 3 hydrogen atoms appear in the reactants, there
must be three hydrogens in the products. If the coefficient
of ammonia reactant is 1, the coefficient of water product
must be 3/2.
1 NH3 + O2
1 NO +
H2O
Step 3: balance oxygen atoms
There are 1+3/2=5/2 moles of oxygen atoms in the products.
Making the coefficient of O2 equal to 5/4
will produce the same number of moles of oxygen in the
reactants.
1 NH3 +
O2
1 NO +
3/2 H2O
Step 4: Obtain lowest whole number coefficients
Multiply all coefficients in the result of the previous
step by 4.
4 NH3 +
5 O2
4 NO +
6 H2O