00:01
This chemical equation for the combustion of heptane starts with the chemical formula for h -tane, c7h -16.
00:08
Now, at room temperature, this is usually a liquid, so we'll put parentheses l there.
00:13
All combustion reactions mean we're burning something, and in order to burn something, that means you're reacting it with oxygen gas, which has the symbol o subscript 2, parentheses g.
00:25
The products of a combustion reaction are carbon dioxide.
00:30
Dioxide gas and water vapor, h2o.
00:37
So we'll put parentheses gs for their phases.
00:39
Now we'll want to balance this equation by putting coefficients in front of some or all of these chemicals.
00:46
And we'll start by balancing the carbons.
00:50
There are seven carbons on the reactant side, so we will put a seven coefficient in front of the carbon dioxide to give us seven carbons on the product side.
01:00
Now we'll balance the hydrogens next.
01:04
There are 16 hydrogens on the reactant side, so we'll put an 8 in front of the water molecules, because 8 times 2 gives us 16 hydrogens on the product side.
01:17
If we produce 8 water molecules, we'll be producing 16 hydrogen atoms.
01:24
Then finally, that leaves us with the oxygens to balance.
01:27
And what we want to do is count up all the oxygens on the product side.
01:31
So the coefficient on carbon dioxide is seven times it subscript two.
01:36
That gives us 14 oxygens from the seven carbon dioxide plus we have another eight oxygens from these waters.
01:47
So we have 14 plus eight.
01:50
That gives us 22 total oxygens on the product side, which means we need to put an 11.
01:57
Coefficient in front of the oxygen on the reactant side because 11 times 2 will give us 22 oxygens.
02:04
And that is the complete balanced chemical equation for the combustion of heptane.
02:10
The combustion of wax will start with the chemical formula for wax, and generally at room temperature wax is a solid, so we'll put a prerencey s there...