Chemistry - Chemical Equilibrium Question with Solution | TestHub
\begin{gathered}{}\text{For}\text{ }\text{the}\text{ }\text{given}\text{ }\text{reaction:}\text{ }\text{2A(s)}\text{ }\text{+}\text{ }\text{B(g)}\text{ }\rightleftharpoons\text{ }\text{C(g)}\text{ }\text{+}\text{ }\text{2D(s)}\text{ }\text{+}\text{ }\text{E(s),}\text{ }\text{the}\text{ }\text{extent}\text{ }\text{of}\text{ }\\{}\text{reaction}\text{ }\text{of}\text{ }\text{B}\text{ }\text{was}\text{ }\text{found}\text{ }\text{to}\text{ }\text{be}\text{ }\text{20%}\text{ }\text{at}\text{ }\text{300}\text{ }\text{K}\text{ }\text{and}\text{ }\text{24%}\text{ }\text{at}\text{ }\text{500}\text{ }\text{K.}\text{ }\text{The}\text{ }\text{rate}\text{ }\text{of}\text{ }\\{}\text{backward}\text{ }\text{reaction}\end{gathered}
Options:
Answer:
Solution:
\begin{gathered}\text{The backward rate is }r_b=k_b[C]\text{; solid activities are constant.}\\\text{Compression increases }[C]\text{ and therefore increases the backward rate.}\\\text{The gas stoichiometry is 1:1, so pressure does not change the equilibrium}\\\text{conversion, but it does change concentrations and the equilibrium rate.}\\\text{Conversion rises from 20% at 300 K to 24% at 500 K, so }K\text{ increases:}\\\text{the forward reaction is endothermic. Both rate constants rise with temperature.}\\\text{Thus the backward rate increases with pressure and temperature: option (a).}\\\text{Correction: the printed book key gives (d), which overlooks the pressure effect on rate.}\end{gathered}
