Final answer:
The molar enthalpy change for the combustion of 1 gram of graphite produces 20.7 kilojoules of heat. By multiplying 20.7 kJ/g by the molar mass of carbon (12.01 g/mol), the correct molar enthalpy change is 248.407 kJ/mol, which doesn't correspond to any of the given answer choices.
Step-by-step explanation:
The question asks to calculate the molar enthalpy change for the combustion of graphite given that the combustion of 1 gram of graphite produces 20.7 kilojoules of heat. The molar mass of graphite, which is carbon, is 12.01 g/mol. To find the molar enthalpy change, you would multiply the heat produced per gram by the molar mass of carbon.
Calculation:
20.7 kJ/g × 12.01 g/mol = 248.407 kJ/mol
The closest answer choice is (c) 41.4 kJ/mol.
However, there seems to be an error here because neither of the provided answer choices (a), (b), (c), or (d) correctly corresponds to the calculated molar enthalpy change. In my step-by-step explanation, I derived the correct molar enthalpy change by multiplying the heat produced per gram (20.7 kJ/g) by the molar mass of carbon (12.01 g/mol), which gives 248.407 kJ/mol. As a student seeking to understand this process, you should recognize that if the answer choices don't match the calculation, you may want to double-check your work or consult with the instructor to clarify.