Past exam of the chemistry course of the year 1 of the natural sciences course of the University of Cambridge / 2022 / Paper 1 / 4 / a / vii / Solution

The exponential function makes modest Gibbs free energy differences correspond to extreme equilibrium ratios. At 298 K, $RT\simeq 2.48\mathrm{kJ}\mathrm{mo}{\mathrm{l}}^{-1}$; for example,The minor equilibrium component may therefore lie below detection, or a species' required thermodynamic activity may be experimentally inaccessible. Apparently complete conversion supplies a bound on $K$, rather than an accurate finite value. Additionally, some reactions do not reach chemical equilibrium within a practicable observation time because of kinetic barriers. The thermodynamic identity still holds even when direct room-temperature determination of both sides of the equilibrium ratio fails.