Past exam of the chemistry course of the year 1 of the natural sciences course of the University of Cambridge / 2022 / Paper 1 / 5 / a / i

With the forward direction defined as cis-to-trans, the elementary steps have rates $k_1[\mathrm{cis}]$ and $k_{-1}[\mathrm{trans}]$. One trans molecule is gained per forward event and lost per reverse event, soEach rate constant has units ${\mathrm{s}}^{-1}$, and the right side has units of concentration per unit time. This net rate can have either sign, even though the individual event rates are nonnegative.