# Module 4.1 - Chemical Equations

### Balanced Chemical Equations

You surely have heard that matter can not be created or destroyed. This law applies to chemical reactions. In a chemical reaction, atoms can not be created or destroyed; they simply rearrange themselves to form new products. This law has an effect on the coefficients of a chemical equation. All of the atoms that were present at the beginning of the reaction as reactants also need to be present at the end of the reaction as products. A chemical equation that is written so this is true is said to be balanced.

Was the chemical equation previously discussed balanced? Let's take a closer look:

If this equation is balanced, the same atoms (in number and identity) will be present as reactants and products.

To see if the equation is balanced, we can follow two steps:

Step 1: Break each molecule up into the individual atoms. Count the number of each type of atom in each type of molecule.

Fill in the total number of atoms present for each type of molecule.

 Click here if you would like to see molecules broken into atoms. C O C H H O O

Step 2: Count the number of atoms of each type on each side of the equation (for the reactants and for the products). If each side of the equation has the same number of atoms of a given element, that element is balanced. If all elements are balanced, the equation is balanced.

Fill in the following table for this reaction:

 Reactant(s) Product(s) C C O O H H
 Is this equation balanced? Yes No

Click on image below to see a pictorial representation of this. Clicking on this mouse will reset the image.

 Chemical Equations