Stoichiometry


Balancing Equations

Chemical equations must be balanced by stoichiometric coefficients in front of each reactant and product such that there are an equal number of moles of each element on each side of the equation. With the stoichiometric coefficients of 2, 6, and 8 in the equation above, the carbon atoms and hydrogen atoms are both balanced: There are 6 moles of carbon atoms on each side of the equation and there are 16 moles of hydrogen atoms on each side. The coefficient x must be such that there are an equal number of oxygen atoms on each side:

Since there are 20 atoms of oxygen on the right (6 x 2 + 8 = 20) and 2 atoms of oxygen on the left from the first reactant, x must be equal to 9 so that there are a total of 20 atoms of oxygen on the left.