What is the balanced equation for combustions of propane gas that yields carbon dioxide and water?

1 Answer

A combustion reaction is a reaction between a hydrocarbon burned in oxygen to form carbon dioxide and water.

A hydrocarbon is a molecule composed of carbon and hydrogen in this case propane. The pro- prefix tells us we have 3 carbon.
For hydrocarbons that end in the suffix -ane the formula is CnH2n+2. This means we need 8 hydrogen, making the formula C3H8.

Now we can format the basic reaction.

C3H8+O2CO2+H2O

A reminder that oxygen is a diatomic molecule as a gas, O2.

Begin by balancing the hydrogen by adding a coefficient of 4 in from of the water.

C3H8+O2CO2+4H2O

This balances the hydrogen at 8. Now add a a coefficient of 3 in from of the carbon dioxide.

C3H8+O23CO2+4H2O

This balances the carbon at 3. We now have 10 oxygen on the on the product side, 6 from CO2 and 4 from H2O. We need to add a coefficient of 5 in front of the oxygen to balance the oxygen at 10.

C3H8+5O23CO2+4H2O

The combustion reaction is now balanced.

I hope this was helpful.
SMARTERTEACHER