To be successful with this question, you need to understand what a combustion reaction is and you need to know how to balance a chemical equation. A
combustion reaction involves the reaction of a substance with oxygen gas (O
2). The most common combustible substance is a hydrocarbon - a substance containing the elements carbon and hydrogen. In this case, the substance undergoing combustion is a hydrocarbon. The products of hydrocarbon combustion are carbon dioxide (CO
2) and water vapor (H
2O).
Understanding this about combustion allows you to quickly get through
Step 1 and
Step 2 of the question. That leaves
Step 3 in which you have to identify the lowest possible whole number coefficients.
The infographic below describes a step-by-step method for balancing a chemical equation. Study the method and then prepare to apply it to this question. There are some additional specifics after the graphic that pertain specifically to this question.
Some Specifics About This Question Group
If you apply the step-by-step method to this question, then you will likely begin by balancing the element hydrogen by inserting a coefficient in front of the product H
2O. And balance the element carbon by inserting a coefficeint in front of the product CO
2. Finally, you will balance the oxygen by inserting a coefficient in front of the reactant O
2. Then you should be done.