Calculating ΔG
A reaction has ΔH = −100 kJ/mol and ΔS = −200 J/mol·K. What is ΔG at 300 K?
Answer B: explanation for every choice
A
This adds TΔS instead of subtracting it.
B
Correct. ΔG = ΔH − TΔS = −100 − (300)(−0.200) = −100 + 60 = −40 kJ/mol.
C
This reverses the sign of the result.
D
This doesn't convert ΔS from J to kJ.
TakeawayΔG = ΔH − TΔS. Convert ΔS to kJ first.
Equation usedGibbs free energy
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