Final answer:
To calculate the percent yield, we convert 28.16 g of CO2 formed into moles, determine the limiting reagent, calculate the theoretical yield of CO2 in grams based on the moles of limiting reagent, and then divide the actual yield by the theoretical yield and multiply by 100.
Step-by-step explanation:
The question involves calculating the percent yield of a chemical reaction where octane (C8H18) reacts with oxygen (O2) to produce carbon dioxide (CO2) and water (H2O). The balanced chemical equation shows that 2 moles of octane react with 25 moles of oxygen to yield 16 moles of carbon dioxide and 18 moles of water. Given that 28.16 g of CO2 is formed from the reaction of 8.000 moles of C8H18 with 4.000 moles of O2, we must find the actual yield and compare it to the theoretical yield to find the percent yield.
First, we determine the number of moles of CO2 that 28.16 g corresponds to by using the molar mass of CO2, which is 44.010 g/mol. We then need to compare this to the theoretical yield, which is based on the limited reagent. In this case, oxygen is the limiting reagent since there is not enough oxygen to react with all the octane present.
Since the reaction requires 25 moles of oxygen to yield 16 moles of CO2, and we only have 4.000 moles of oxygen, we will only get (16/25) * 4.000 moles of CO2 theoretically. To find the theoretical yield in grams, we multiply the number of moles by the molar mass of CO2. Finally, we divide the actual yield by the theoretical yield and multiply by 100 to get the percent yield.