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The standard enthalpy of formation and the standard entropy of gaseous benzene are 82.93 kJ/mol and 269.2 J/K*mol, respectively. Calculate ΔH° , ΔS° , and ΔG° for the following process at 25.00°C.

C6H6(l) ------> C6H6(g)

User Luizgrs
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2 Answers

6 votes

Final answer:

The standard enthalpy change (ΔH°) for the process C6H6(l) → C6H6(g) is 82.93 kJ/mol. The standard entropy change (ΔS°) for the process is 269.2 J/K*mol. The standard free energy change (ΔG°) for the process is 7361.033 kJ/mol.

Step-by-step explanation:

The standard enthalpy change, ΔH°, for the process C6H6(l) → C6H6(g) can be calculated using the standard enthalpy of formation of benzene in the gaseous state and the liquid state. The equation for ΔH° is ΔH° = ΣΔH°(products) - ΣΔH°(reactants). In this case, since benzene is the only product and there are no reactants, the equation simplifies to ΔH° = ΔH°(C6H6(g)). Therefore, ΔH° = 82.93 kJ/mol.

The standard entropy change, ΔS°, for the process can be calculated using the standard entropy of benzene in the gaseous state and the liquid state. The equation for ΔS° is ΔS° = ΣΔS°(products) - ΣΔS°(reactants). Similar to the calculation for ΔH°, since benzene is the only product and there are no reactants, the equation simplifies to ΔS° = ΔS°(C6H6(g)). Therefore, ΔS° = 269.2 J/K*mol.

The standard free energy change, ΔG°, for the process can be calculated using the equation ΔG° = ΔH° - TΔS°, where T is the temperature in Kelvin. Since the temperature is given as 25.00°C, we need to convert it to Kelvin by adding 273.15. Therefore, T = 25.00°C + 273.15 = 298.15 K. Substituting the values into the equation, we get ΔG° = 82.93 kJ/mol - (298.15 K)(269.2 J/K*mol) = 7361.033 kJ/mol.

User Amith Dissanayaka
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3 votes

Answer:

ΔG° = 2708.4J/mol , ΔS° = 269.2 J/K*mol, ΔH° = 82.93 kJ/mol

Step-by-step explanation:

The relationship between all three parameters mentioned is given as;

ΔG° (change in free energy) =ΔH (change in enthalpy) −TΔS (temperature * change in entropy)

ΔH° = 82.93 kJ/mol = 82.93 * 1000 = 82930J/mol

ΔS° = 269.2 J/K*mol

T = 25 + 273 = 298K (Converting to Standard unit of Kelvin)

ΔG° = ΔH° - TΔS°

ΔG° = 82930 - 298 * 269.2

ΔG° = 82930J/mol - 80221.6J/mol

ΔG° = 2708.4 J/mol

User Inu
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