Balance this equation?

Question

C8H18 + 02 ---> CO2 + H20

Answer 1

2 C8H18 + 25 O2 ---> 16 CO2 + 18 H2O

Answer 2

1st step: Look at the number of C and H in octane. Put a 8 in CO2 and a 9 in H2O to balance the 8 carbon atoms and 18 hydrogen atoms on both sides of the equation

C8H18 + O2 --> 8CO2 + 9H2O

2nd step: Count the number of oxygen atoms on the right side of the equation, giving a total of [8 x 2 + 9] = 25

Since oxygen gas has to be written as O2 and not just O, we then put 1/2 of 25 on the oxygen (which is 12.5), to make up 25 O on the LEFT side of the equation.

C8H18 + 12.5 O2 --> 8CO2 + 9H2O

This is already balanced. However, that said, most the the Chemistry teachers insist (for some strange reasons known only to themselves....as they were taught that way when they were students long time ago) that you cannot put 12.5

Please go and ask your Chemistry teacher, without being rude to them, what the 12.5 number stand for. It actually stands for 12.5 MOLES and NOT 12.5 molecules!

Since most Chemistry teachers insist you remove the decimal point.......multiply the whole equation by 2: giving

2C8H18 + 25O2 --> 16CO2 + 18H2O

There you are. I teach my students in Singapore at PL Edcation Centre, Singapore to do in this way so that balancing equation is not a matter of guessing. By the way, I am also a Chemistry book writer....hehehehe

Answer 3

Start with one element, then move onto others. Start with carbon in this case. One both sides must be a multiple of 8 carbons. Let's go with that. There also must be multiples of 18 hydrogens, so go with that. Oxygen must be in a multiple of 2, so we can make that fit later. We get:

1C8H18 + 12.5 02 --> 8CO2 + 9H2O

This doesn't work. We can't have a half molecule. Multiply it out on both sides and get:

2 C8H18 + 25 O2 --> 16CO2 + 18H2O

Is that right? You need to double check me to make sure I did it right, and that you understand it.

Answer 4

When balancing equations that involve burning hydrocarbons, it is often helpful to double the number of hydrocarbon molecules to start. This is especially true of fully saturated hydrocarbons, those with the general formula CnH2n+2. The reason is that you end up with and extra oxygen that becomes difficult to balance unless you have an even number of them in the products. This equation balances with 2 hydrocarbons, 25 oxygens, 16 carbon dioxides and 18 oxygens.

Answer 5

you cannt balance this because you are missing O in your experiment