Consider the reaction $$\begin{array} { l } P _ { s o l }\underset { k _ { - 1 } } { \stackrel { k _ { 1 } } { \rightleftarrows } }Q _ { - s o l } + e ^ { - } \ A _ { s ol } ^ { - } \underset { k _ { - 2 } } { \stackrel { k _ { 2 } } { \rightleftarrows } } A _ { a d s } + e ^ { - } \ \end{array}$$ -The mass balance equation for fractional surface coverage of A_ads is given by A) $$\Gamma \frac { d \theta } { d t } = k _ { 1 } \left[ P _ { s d } \right] - k _ { - 1 } \left[ Q _ { s ol } \right] + k _ { 2 } \left[ A _ { s o l } ^ { - } \right] - k _ { - 2 } \theta$$ B) $$\Gamma \frac { d \theta } { d t } = k _ { 2 } \left[ A _ { s d } ^ { - } \right] ( 1 - \theta ) - k _ { - 2 } \theta$$ C) $$\Gamma \frac { d \theta } { d t } = k _ { 1 } \left[ P _ { s o l } \right] ( 1 - \theta ) - k _ { - 1 } \left[ Q _ { s o l } \right] \theta + k _ { 2 } \left[ A _ { s o l } ^ { - } \right] ( 1 - \theta ) - k _ { - 2 } \theta$$ D) $$\Gamma \frac { d \theta } { d t } = k _ { 2 } \left[ A _ { s ol} ^ { - } \right] - k _ { - 2 } \theta$$

Question

Quizplus · Accepted Answer

The correct mass balance equation for the fractional surface coverage ($\theta$) of $A_{ads}$ involves the rate of adsorption, which is proportional to the concentration of $A_{sol}^-$ and the available surface area ($1-\theta$), and the rate of desorption, which is proportional to the surface coverage ($\theta$). This is accurately represented in option B, where $k_2[A_{sol}^-](1-\theta)$ accounts for adsorption and $k_{-2}\theta$ for desorption.

Consider the Reaction -The Mass Balance Equation for Fractional Surface Coverage of Aads

Consider the Reaction -The Mass Balance Equation for Fractional Surface Coverage of A_ads