All questions
AP Chemistry
5.11 Catalysis
5.7 Introduction to Reaction Mechanisms
5.6 Reaction Energy Profile
AdvancedMCQDrawing RepresentationsMathematicalConceptualExperimental14k
A student investigates the reversible reaction

\[ \text{A(aq)} \rightleftharpoons \text{B(aq)} \]

at \(298\ \text{K}\). The student assigns each catalyzed pathway one of the following labels: homogeneous nonenzymatic, heterogeneous, or enzymatic. The observations and measured activation energies are shown below.

PathwayObservation\(E_{a,\mathrm{f}}\) \((\text{kJ mol}^{-1})\)\(E_{a,\mathrm{r}}\) \((\text{kJ mol}^{-1})\)
\(\text{U}\)No catalyst is present.\(80\)\(50\)
\(\text{P}\)\(\text{C(aq)}\) forms \(\text{AC(aq)}\) in an elementary step and is regenerated in a later step.\(55\)\(25\)
\(\text{Q}\)\(\text{A(aq)}\) adsorbs onto \(\text{M(s)}\), reacts on its surface, and desorbs as \(\text{B(aq)}\).\(45\)\(15\)
\(\text{R}\)A dissolved protein \(\text{E(aq)}\) binds \(\text{A(aq)}\) at a shape-specific active site, releases \(\text{B(aq)}\), and is regenerated.\(40\)\(10\)

Which statement correctly classifies pathways \(\text{P}\), \(\text{Q}\), and \(\text{R}\) and predicts how each catalyst affects the equilibrium ratio \(\dfrac{[\text{B}]}{[\text{A}]}\) relative to pathway \(\text{U}\)?

Log In to Continue

Accounts are free! Log in to try this question, see explanations, save progress, and more!

Tools for a 5