Hey Rachel!

Did the first equation show up for you on your browser? I was using firefox and the image didn't load. That could have been why this problem gave you a bit more trouble than usual!

To solve this question, you need to 1. balance the combustion equation provided, 2. calculate the number of moles in your starting material, and 3. apply PV=nRT.

1. In a general combustion equation:

CnHn + O2 --> CO2 + H2O

Given that we are using C12H23, we balance the equation, and get:

4C12H23 + 71O2 --> 48CO2 + 46H2O

Both CO2 and H2O would be gas state at the high temperature of a combustion. So therefore, both should be included in your calculation of the total gas produced.

2. Now you are told you are using 167 g of C12H23. If you calculate the total molar mass of the compound, you will find that it is 167 g/mol. Therefore, you are looking at using 1 mol of the compound.

We know, based on our balanced equation, that for every 4 mols of our starting material C12H23, we get 48 mols of CO2 and 46 mols of H2O. So, use (48+46)/4 = 23.5 mols.

3. Then, if you apply PV=nRT with the given values, you will find that your total volume is close to 4000L, and therefore, the answer is D.

Hope this helps! If you need more assistance, please reply to this post.

Cheers, and happy studying! :)