Why is it important to reduce coefficients in a balanced equation to the lowest possible whole-number ratio?

Answer 1

Coefficients tells us the ratio which the reactants in a chemical reaction react in. For example, consider a balanced chemical equation between sulfuric acid and sodium hydroxide:

H2SO4(aq) + 2NaOH(aq) --> Na2SO4(aq) + H2O(l)

We can see from this equation that the H2SO4:NaOH ratio is 1:2. This tells us that for every one sulfuric acid involved in the reaction, there will be two sodium hydroxide involved. Chemical equations must be balanced because new atoms cannot magically appear or disappear according law of conservation of mass. In a chemical reaction, there is no creation or elimination of atoms, only a rearrangement of atoms so the number of atoms on both sides must be the same. Balancing chemical equations require the number to be placed as a coefficient because if the number is placed elsewhere (i.e. within the chemical formula), you are changing the composition of that molecule.

Answer 2

Because it's a little hard to create, say, half of a hydrogen atom. Or half of a carbon dioxide molecule. Take, for instance, the basic combustion equation (methane + oxygen = carbon dioxide + water):

• CH4 + 2O2 = CO2 + 2H2O

Rearranging that to determine, say, what one O2 molecule would react with gives:

• O2 + (0.5)CH4 = (0.5)CO2 + H2O

Now... how precisely do you get (0.5)CH4? Do you have half of a carbon atom bonded to two hydrogen atoms? What would half of a carbon atom BE, anyways? Three protons + three neutrons + three electrons? That's something else entirely - a lithium-6 atom, to be specific.

Answer 3

To show the lowest whole-number ratio of the amounts of all the reactants and products. In other words, to show the smallest number of particles of the substance involved in the reaction.