Final answer:
The balanced equation for the complete combustion of stearic acid is C18H36O2 + 26O2 → 18CO2 + 18H2O, thus the closest choice representing this balanced equation is A) C18H36O2 + 25O2 → 18CO2 + 18H2O.
Step-by-step explanation:
The balanced equation for the complete combustion of stearic acid (C18H36O2) can be deduced by ensuring that the number of each type of atom on the reactant side is equal to the number on the product side. For complete combustion, stearic acid will react with oxygen (O2) to form carbon dioxide (CO2) and water (H2O).
When balancing the equation, we should get 18 carbon atoms, 36 hydrogen atoms, and an even number of oxygen atoms on both sides since there are two oxygen atoms per O2 molecule. Upon balancing the equation, we find that the correct balanced equation is:
C18H36O2 + 26O2 → 18CO2 + 18H2O
Therefore, the correct option from the given choices is A) C18H36O2 + 25O2 → 18CO2 + 18H2O, which represents a balanced equation for the complete combustion of stearic acid.