Given the following data relevant to the combustion of ethanol, determine the free energy of formation for liquid ethanol, C₂H₅OH. (C₂H₅OH, l) -930.7 kJ/mol (CO₂, g) -394.4 kJ/mol (H₂O, g) -105.6 kJ/mol

Question

Quizplus · Accepted Answer

The free energy of formation of liquid ethanol can be calculated using the equation:

ΔGf°(l) = ΣΔGf°(products) - ΣΔGf°(reactants)

The balanced chemical equation for the combustion of ethanol is:

C2H5OH(l) + 3O2(g) → 2CO2(g) + 3H2O(l)

Using the given data, we can calculate the free energy of formation of liquid ethanol as follows:

ΔGf°(l) = [2ΔGf°(CO2(g)) + 3ΔGf°(H2O(l))] - [ΔGf°(C2H5OH(l)) + 3ΔGf°(O2(g))]
ΔGf°(l) = [2(-393.4 kJ/mol) + 3(-285.8 kJ/mol)] - [(-10930.7 kJ/mol) + 3(-0 kJ/mol)]
ΔGf°(l) = -174.9 kJ/mol

Therefore, the best choice is C: (F1F1F1S1F1F1F10174.9 kJ/mol).

Given the Following Data Relevant to the Combustion of Ethanol