The value of Gibbs energy change at STP will be ________ (in kJ) The s...
Using this formula Δ G° = Δ H° - T Δ S°
First we have to convert temperature to Kelvin scale = 25+ 273 = 298 K
And now. placing the values in the above equation.
(exothermic means negative enthalpy change and 100 J = 0.1 kJ)
ΔG° = - 20 - 298 x 0.1
= - 20 - 29.S
= -49.8 kJ
View all questions of this test
The value of Gibbs energy change at STP will be ________ (in kJ) The s...
The Gibbs energy change (ΔG) is a thermodynamic property that determines the feasibility of a reaction. It is related to the enthalpy change (ΔH) and entropy change (ΔS) through the equation ΔG = ΔH - TΔS, where T is the temperature in Kelvin.
Given that the standard enthalpy change for the reaction is 20 kJ (exothermic) and the entropy change is 100 J mol-1 K-1, we can calculate the ΔG at STP (25°C and 1 atm pressure).
To convert the enthalpy change from kJ to J, we multiply it by 1000. Therefore, ΔH = 20 kJ = 20,000 J.
Now, let's calculate the value of ΔG at STP:
ΔG = ΔH - TΔS
Here, T = 25°C = 298 K (STP)
ΔG = 20,000 J - (298 K)(100 J mol-1 K-1)
ΔG = 20,000 J - 29,800 J mol-1
Now, we need to convert the ΔG from J mol-1 to kJ mol-1 by dividing it by 1000:
ΔG = (20,000 J - 29,800 J mol-1) / 1000
ΔG = -9,800 J mol-1 / 1000
ΔG = -9.8 kJ mol-1
Since the concentration of various components is unity, the value of ΔG is the same as the Gibbs energy change per mole of the reaction.
Therefore, the value of ΔG at STP is -9.8 kJ mol-1.
Now, to find the value of ΔG at STP in kJ, we need to divide it by the Avogadro constant, which is 6.022 × 10^23 mol-1:
ΔG = -9.8 kJ mol-1 / (6.022 × 10^23 mol-1)
ΔG = -1.627 × 10^-23 kJ
Rounding to one decimal place, the value of ΔG at STP is approximately -0.0 kJ.
Therefore, the correct answer between '-49.9,-49.1' is incorrect. The correct value of ΔG at STP is approximately -0.0 kJ.