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A <-> B equilibrium energy

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A <-> B equilibrium energy diagram
Two interconverting species A and B have an equilibrium ratio that depends on their difference in energy and the temperature, according to the equation ΔG=RT*ln(k), where k is the equilibrium constant. This can be derived from the Arrhenius (temp-rate dependence) equations for the forward and backwards reactions.
Ratio a:b
At temperature
Temperature x

Energy difference
a:b ratio at temp. x
Proportion of b at temp. x
Equilibrium constant
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Enter a measured A:B ratio and the temperature it was measured at. The calc then gives the energy difference between the A and B states. This is either negative or positive, depending whether A or B is the lowest in energy.
If you also enter a "temperature x" in the third input box, the calc gives the expected equilibrium A:B ratio (and the proportion of B as a percentage) for that temperature.