How would I find the number of Kcal energy released per mole of C8 H18 combusted?
To find the number of kilocalories (Kcal) of energy released per mole of C8H18 combusted, you will need to calculate the heat of combustion of C8H18 and convert it to Kcal.
Here's how you can proceed:
Step 1: Determine the balanced chemical equation for the combustion of C8H18 (octane).
The balanced equation for the combustion of octane is:
C8H18 + 12.5O2 → 8CO2 + 9H2O
Note: The coefficients in the balanced equation represent the stoichiometric ratios between reactants and products.
Step 2: Calculate the heat of combustion of octane.
The heat of combustion is the energy released when one mole of a substance completely reacts with oxygen. The heat of combustion for octane is approximately -5471 Kcal/mol.
Step 3: Convert the heat of combustion from joules to kilocalories.
To convert from joules to kilocalories, divide the value by the conversion factor:
1 kilocalorie (Kcal) = 4184 joules (J)
Dividing -5471 Kcal/mol by 4184 J/Kcal, you get approximately -1.31 × 10^6 J/mol.
Step 4: Convert joules/mol to kilocalories/mol.
Finally, convert the value from joules/mol to kilocalories/mol by dividing by 1000:
-1.31 × 10^6 J/mol ÷ 1000 = -1.31 × 10^3 Kcal/mol
Therefore, the number of Kcal of energy released per mole of C8H18 combusted is approximately -1.31 × 10^3 Kcal/mol. Note that the negative sign indicates the energy release during the combustion process.