A balanced reaction equation must have the same number of atoms of each element on both sides of the equation. The reaction
C2H5OH + 3O2 → 2CO2 + 3H2O
represents the combustion of ethanol. Count the atoms of each element on both sides of the reaction.
How many of each atom are there on the reactants side?
C atoms: 2
H atoms: 6
O atoms: 2
How many of each atom are there on the products side?
C atoms: 2
H atoms: 6
O atoms: 6