The migration speed of substituted benzoic acids results from the combined effects of

electroosmotic flow and electrophoretic mobility.

The voltage applied to the $0\mathrm{.}500-$m$-$long capillary is $2\mathrm{.}50{10}^{4}V.$

The neutral marker molecule carried by EOF was measured to travel $0\mathrm{.}400m$ in $188s$ from the inlet

to detector. Migration times of benzoate and $2-$methylbenzoate are $340s$ and $371s,$ respectively.

Find the electroosmotic mobility and apparent mobility of the two analytes. Then determine the

effective $($or and electrophoretic mobilities$)$ the two analytes.