Past exam of the chemistry course of the year 3 of the natural sciences course of the University of Cambridge / 2022 / Paper 4 / 64 / d / iii

For simultaneous competitive adsorption, use the butyric-acid constant inferred in part (c), $b_b\simeq 1.21{\mathrm{m}}^3\mathrm{mmo}{\mathrm{l}}^{-1}$, and $C_b=10^6\mathrm{mmol}{\mathrm{m}}^{-3}$:The propionic-acid rate is therefore approximatelyThe abundant, more strongly adsorbing butyric acid occupies most common sites, reducing propionic conversion by roughly a factor of $35$. This calculation follows the requested competitive Langmuir model despite the physical concern about the fitted saturation density noted earlier.