How to quickly balance chemical equations

How to Balance Chemical Equations: 3 Easy Steps

A chemical equation tells you what happens during a chemical reaction. A balanced chemical equation has the right number of reactants and products to keep the law of measure


A chemical equation tells you what happens during a chemical reaction. A balanced chemical equation has the correct number of reactants and products to satisfy the law of conservation of mass.

In this article, we're going to talk about what a chemical equation is, how to balance chemical equations, and give you some examples to help you balance chemical equations.

What is a chemical equation?

Simply put, A chemical equation tells you what happens in a chemical reaction. This is what a chemical equation looks like:

Fe + O2 → Fe2O3

On the left side of the equation are the reactants. These are the materials that you start a chemical reaction with.

On the right side of the equation are the products. The products are the substances that are produced through a chemical reaction.

In order for a chemical reaction to be correct, it has to satisfy something called the law of conservation of mass. This means that no mass can be created or destroyed during a chemical reaction. This means that each side of the chemical equation must have the same mass amount because the mass amount cannot be changed.

If your chemical equation has different masses on the left and right sides of the equation, then you need to balance your chemical equation.

How to balance chemical equations - explanation and example

Balancing chemical equations means that you are writing the chemical equation correctly so that there is the same mass on each side of the arrow.

In this section, we'll explain how to balance a chemical equation, using a real life example, the chemical equation that occurs when iron rusts:

Fe + O.2 → Fe2Ö3

# 1: Identify the products and reactants

The first step in balancing a chemical equation is to identify your reactants and your products. Remember, your reactants are on the left hand side of your equation. The products are on the right.

For this equation, our reactants are Fe and O.2. Our products are Fe2 and O3.

# 2: Write the number of atoms

Next you need to determine how many atoms of each element there are on each side of the equation. You can do this by looking at the indices or coefficients. If there is no index or coefficient, then you only have one atom of something.

Fe + O.2 → Fe2Ö3

On the reactant side we have one atom of iron and two atoms of oxygen.

On the product side, we have two iron atoms and three oxygen atoms.

If you write down the number of products, you can find that the equation is not balanced because there are different amounts of each atom on the reactant side and the product side.

That said, we need to add coefficients to balance this equation.

# 3: add coefficients

I mentioned earlier that there are two ways to know how many atoms of a given element there are in a chemical equation: by looking at the indices and the coefficients.

When you balance a chemical equation, you change the coefficients. They never change indexes.

A coefficient is an integer multiplier. To balance a chemical equation, add these integer multipliers (coefficients) to make sure there are the same number of atoms on each side of the arrow.

The following should be noted about coefficients: They apply to every part of a product. Take, for example, the chemical equation for water: H2O. When you added a coefficient to get 2H2O, then the coefficient is multiplied over all the elements present. So, 2H2O means you have four hydrogen atoms and two oxygen atoms. You don't just multiply by the first element present.

So, in our chemical equation (Fe + O.2 → Fe2Ö3) any coefficient you add to the product must be reflected with the reactants.

Let's look at how this chemical equation can be balanced.

On the product side, we have two iron atoms and three oxygen atoms. Let's tackle iron first.

The first time you look at this chemical equation, you might think that something like this works:

2Fe + O.2 → Fe2Ö3

While this balances the iron atoms (two on each side), oxygen is still unbalanced. That means we have to keep looking.

If we take iron first, we know we're going to be working with a multiple of two because there are two iron atoms on the product side.

Knowing that using two as a coefficient won't work, let's try the closest multiple of two: four.

4Fe + O.2 → 2Fe2Ö3

This creates a balance for iron by having four atoms on each side of the equation. Oxygen is not fully balanced yet, but on the product side we have six oxygen atoms. Six is ​​a multiple of two, so we can work with that on the reactant side where there are two oxygen atoms.

This means that we can write our balanced chemical equation like this:

4Fe + 3O2 → 3Fe2Ö3

3 Great Sources for Balancing Chemical Equations

There are many places where you can practice balancing chemical equations online.

Here are some exercise problem places you can use:

  • Khan Academy: 7 exercise problems
  • ScienceGeek: 15 Exercise Problems
  • TemplateLab: 49 free downloads of worksheets for balancing chemical equations

Balancing Chemical Equations: Key Findings

Balancing chemical equations seems complicated, but it really isn't that difficult!

Your main goal in balancing chemical equations is to make sure that there are the same amount of reactants and products on each side of the chemical equation arrow.

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