At 298K,
2PCl3(g)+O2(g)---> 2POCl3(l)
Delta H= -620.2kJ
for the reaction and the standard molar entropies are ,PCl3(g)= 311.8J/K,O2(g)= 205.1J/K and POCl3(l)=222.4J/K.
Determine the standard free energy change at 298K.
How??
Hey nevermind, I got this question done:) Thanks anyways
To determine the standard free energy change (ΔG) at 298K, you can use the equation:
ΔG = ΔH - TΔS
where ΔH is the enthalpy change, ΔS is the entropy change, and T is the temperature in Kelvin.
Given:
ΔH = -620.2 kJ
PCl3(g) = 311.8 J/K
O2(g) = 205.1 J/K
POCl3(l) = 222.4 J/K
T = 298 K
Convert the enthalpy change to J:
ΔH = -620.2 kJ * 1000 J/kJ = -620,200 J
Now calculate ΔS for the reaction using the standard entropies:
ΔS = (2 × ΔSPOCl3(l)) - (2 × ΔSPCl3(g)) - (ΔSO2(g))
= (2 × 222.4 J/K) - (2 × 311.8 J/K) - (205.1 J/K)
= -378.8 J/K
Substitute the values into the equation for ΔG:
ΔG = -620,200 J - (298 K × -378.8 J/K)
= -620,200 J + 113,006.4 J
= -507,193.6 J
So, the standard free energy change at 298K is -507,193.6 J.
To determine the standard free energy change (ΔG) at 298K, you can use the equation:
ΔG = ΔH - TΔS
Where:
ΔG is the standard free energy change
ΔH is the enthalpy change
T is the temperature in Kelvin
ΔS is the entropy change
Given:
ΔH = -620.2 kJ (negative because the reaction is exothermic)
T = 298 K
ΔS for PCl3(g) = 311.8 J/K
ΔS for O2(g) = 205.1 J/K
ΔS for POCl3(l) = 222.4 J/K
First, convert ΔH from kJ to J:
ΔH = -620.2 kJ = -620,200 J
Now, we can calculate ΔG using the formula:
ΔG = ΔH - TΔS
Substituting the given values:
ΔG = -620,200 J - (298 K)(2 * 311.8 J/K + 205.1 J/K - 2 * 222.4 J/K)
Simplifying the equation:
ΔG = -620,200 J - (298 K)(623.6 J/K + 205.1 J/K - 444.8 J/K)
ΔG = -620,200 J - (298 K)(383.9 J/K)
ΔG = -620,200 J - 114,452 J
ΔG = -734,652 J
The standard free energy change (ΔG) at 298K is -734,652 J.