How to balance chemical equations

When you write an equation for a chemical reaction, the two sides of the equation should balance — you need the same number of each kind of element on both positions.

A law in chemistry, the Law of Conservation of Mass, states, “In an ordinary chemical reaction, the matter is neither created nor destroyed.” This signifies that you have neither gained nor lost any atoms during the reaction. They may be combined differently, but they’re nevertheless there. A chemical equation shows the chemicals that react (the reactants) followed by an arrow followed by the chemicals produced by the reaction (the products).

An example of a chemical equation: Al + O2 -> Al2O3.

Chemical equations must be balanced since anything consumed by the reaction must form a product – we can’t have atoms disappearing or appearing out of nowhere! To balance an equation: we add a coefficient to the front of each element or compound that needs it. Essentially you are multiplying the number of atoms or compounds on one side to match the amount on the other side.

Let’s try an example! We will take the given equation: Al + O2 -> Al2O3. We can see that this is not balanced – there is 1 aluminum on the reactant side and 2 on the product side, and there are 3 on the product side and 2 oxygen’s on the reactant side and. How will we balance it?

First, let’s multiply the aluminum on the reactant side by 2 to match the aluminum amount on the products side. Then we have to deal with the oxygen. There are 2 on the reactant and 3 on the product side – since neither one is a multiple of the other, the best thing to do is find the least common multiple of both of them. This would be 6. (2 x 3 = 6). We can then adjust each side to have 6 oxygen by putting a coefficient of 3 in front of the diatomic reactant oxygen and a 2 in front of the compound on the product side.

Now, however, we see that there is 4 aluminum on the product side, so again we need to adjust the reactant aluminum! We can then change the coefficient of 2 in front of the aluminum to a 4. Finally we have a balanced equation: 4Al + 3O2 -> 2Al2O3. There 4 aluminum on each side and 6 oxygen are on each side!