Calculate the molar heat of combustion of paraffin, expressed in units of kJ/mol. First calculate the thermal energy released when one mole of parafin burns) because one mole of parafin (c25h52) has a mass of 325g, the molar heat of combustion will be 352 times greater than the heat of combustion expressed in units of kJ/g.

Help is much appreciated.

To calculate the molar heat of combustion of paraffin (C25H52) expressed in kJ/mol, we need to follow a step-by-step process:

Step 1: Determine the formula for the combustion reaction: The combustion of paraffin can be represented by the following balanced equation:
C25H52 + 38.5O2 → 25CO2 + 26H2O

Step 2: Determine the molar mass of paraffin: To calculate the molar heat of combustion, we need the molar mass of paraffin. The molar mass of carbon (C) is approximately 12.01 g/mol, and the molar mass of hydrogen (H) is approximately 1.01 g/mol. Therefore, the molar mass of paraffin (C25H52) is calculated as follows:
Molar mass of paraffin = (25 × Molar mass of carbon) + (52 × Molar mass of hydrogen)

Step 3: Convert the mass of paraffin to moles: Given that one mole of paraffin has a mass of 325 g, we can calculate the number of moles by dividing the mass by the molar mass of paraffin:
Number of moles = Mass of paraffin / Molar mass of paraffin

Step 4: Calculate the thermal energy released when one mole of paraffin burns: This can be done by using the balanced equation for the combustion of paraffin and the standard enthalpies of formation for carbon dioxide (CO2) and water (H2O). The standard enthalpy of formation is the heat change when one mole of a substance is formed from elements in their standard states under standard conditions. Looking up the values, we have:
ΔH°f(CO2) = -393.5 kJ/mol
ΔH°f(H2O) = -285.8 kJ/mol

Using these values and the coefficients in the balanced equation, we can calculate the thermal energy released (enthalpy change) when one mole of paraffin burns:
Thermal energy released = (25 × ΔH°f(CO2)) + (26 × ΔH°f(H2O))

Step 5: Calculate the molar heat of combustion: We know that the molar heat of combustion is 352 times greater than the heat of combustion expressed in kJ/g. So, to get the molar heat of combustion (expressed in kJ/mol), we can multiply the thermal energy released by 352:
Molar heat of combustion = Thermal energy released × 352

By following these steps, you can calculate the molar heat of combustion of paraffin expressed in units of kJ/mol.