# Problem: If the standard enthalpy of combustion of ethanol (C 2H5OH(l)) at 298 K is −1368 kJ.mol−1, calculate the standard enthalpy of formation of ethanol. The standard enthalpies of formation of carbon dioxide and liquid water are −393.51 and −285.83 kJ.mol−1, respectively.a. −688.7 kJ.mol−1b. +688.7 kJ.mol−1c. −344.3 kJ.mol−1d. −276.5 kJ.mol−1e. +276.5 kJ.mol−1

###### FREE Expert Solution

Write a balanced reaction for the combustion reaction of ethanol (C2H5OH):

Combustion reaction: a compound reacts with O2(g) and the products are H2O(l) and CO2(g)

C2H5OH(l) + O2(g) → CO2(g) + H2O(l)

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###### Problem Details

If the standard enthalpy of combustion of ethanol (C 2H5OH(l)) at 298 K is −1368 kJ.mol−1, calculate the standard enthalpy of formation of ethanol. The standard enthalpies of formation of carbon dioxide and liquid water are −393.51 and −285.83 kJ.mol−1, respectively.

a. −688.7 kJ.mol−1

b. +688.7 kJ.mol−1

c. −344.3 kJ.mol−1

d. −276.5 kJ.mol−1

e. +276.5 kJ.mol−1