For a certain reaction, Delta H(not) = -76.8 kj and delta S(not) = -217 j/k. If n =3, calculate E for the reaction at 25degrees celcius.
To calculate the standard Gibbs free energy (ΔG°) for a reaction, you can use the equation:
ΔG° = ΔH° - TΔS°
Where:
ΔH° = Standard enthalpy change
ΔS° = Standard entropy change
T = Temperature in Kelvin
First, we need to convert the units of ΔH° and ΔS° to KJ and K, respectively.
ΔH° = -76.8 KJ
ΔS° = -217 J/K
1 KJ = 1000 J, so ΔH° = -76.8 KJ * 1000 J/KJ = -76800 J
ΔS° = -217 J/K
Now, we need to convert the temperature from Celsius to Kelvin:
T(°C) = 25°C
T(K) = T(°C) + 273.15
T(K) = 25°C + 273.15 = 298.15 K
Now we can substitute the values into the equation:
ΔG° = ΔH° - TΔS°
ΔG° = -76800 J - (298.15 K)(-217 J/K)
Calculate the expression within the parentheses:
ΔG° = -76800 J + 64724.155 J
Simplify:
ΔG° = -12075.845 J
Finally, we convert the units back to kilojoules:
ΔG° = -12.08 KJ
Therefore, the standard Gibbs free energy (ΔG°) for the reaction at 25 degrees Celsius is -12.08 KJ.