Calculate the Gibbs free energy change for the combustion of ethane gas in oxygen gas to form carbon dioxide gas and water vapor at a temperature of 25 °C and a pressure of 1 atm, given the following thermodynamic data:Reaction: C2H6(g) + 3.5O2(g) → 2CO2(g) + 3H2O(g)ΔH°rxn = -1560.8 kJ/molΔS°rxn = -283.3 J/K•molUsing the above information, what is the value of the Gibbs free energy change at standard conditions?

Question

Calculate the Gibbs free energy change for the combustion of ethane gas in oxygen gas to form carbon dioxide gas and water vapor at a temperature of 25 °C and a pressure of 1 atm, given the following thermodynamic data:Reaction: C2H6(g) + 3.5O2(g) → 2CO2(g) + 3H2O(g)ΔH°rxn = -1560.8 kJ/molΔS°rxn = -283.3 J/K•molUsing the above information, what is the value of the Gibbs free energy ch

Answer 1

To calculate the Gibbs free energy change  G  at standard conditions, we can use the following equation:G = H - TSwhere H is the change in enthalpy, T is the temperature in Kelvin, and S is the change in entropy.First, we need to convert the temperature from Celsius to Kelvin:T = 25C + 273.15 = 298.15 KNext, we need to convert the entropy from J/Kmol to kJ/Kmol:S = -283.3 J/Kmol   1 kJ / 1000 J  = -0.2833 kJ/KmolNow we can plug in the values into the equation:G =  -1560.8 kJ/mol  -  298.15 K  -0.2833 kJ/Kmol  = -1560.8 kJ/mol + 84.5 kJ/mol = -1476.3 kJ/molThe Gibbs free energy change for the combustion of ethane gas in oxygen gas to form carbon dioxide gas and water vapor at a temperature of 25 C and a pressure of 1 atm is -1476.3 kJ/mol.