Write the balanced equation for the combustion of butane, C₄H₁₀, in oxygen. Here we will assume complete combustion meaning only carbon dioxide gas and water vapor are produced.

In a complete combustion reaction, the products are carbon dioxide and water. The unbalanced equation is written as:

First, we will balance the carbon and hydrogen atoms. It is always a good idea to leave oxygen atoms until last. We see there are 4 carbon atoms on the left side of the equation and only one carbon atom on the right side. Put a 4 in front of CO₂.

Next, balance the hydrogen atoms. There are 10 hydrogen atoms on the reactant side and 2 on the product side of the equation. Place a 5 in front of the water molecule to make 10 hydrogens.

Now, count the oxygen atoms–there are 2 on the reactant side of the equation and a total of 13 oxygen atoms on the product side–8 O atoms from 4 CO₂ and 5 O atoms from 5 H₂O. We see ¹³⁄₂ is equal to 13 oxygen atoms. We can put ¹³⁄₂ in front of the O₂ to give 13 oxygen atoms on the reactant side of the equation.

Now, the equation is balanced for C, H, and O, but we need to remove the fraction from the chemical equation. This is done by multiplying all of the equation coefficients by 2.

We now have a balanced equation.

Back to General Chemistry 1 Study Guides
Back to Tutorials
Back to Videos
Back to Home Page