When finely divided MnO is added to a fresh solution of H O
CHEMISTRY · Single correct · A Level · Chemistry · Kinetics · Kinetics
Problem
When finely divided MnO2 is added to a fresh solution of H2O2, rapid oxygen evolution is observed. Which statement about the role of MnO2 is most accurate?
(a) MnO2 is consumed as a reactant to form soluble Mn2+, which drives the decomposition of H2O2 forward.
(b) MnO2 provides an alternative reaction pathway with a lower activation energy but leaves ΔG∘ unchanged.
(c) MnO2 decreases both the activation energy and ΔG∘, thereby increasing both the rate and the spontaneity of the reaction.
(d) MnO2 shifts the position of equilibrium toward O2 by lowering ΔG∘; the activation energy is unaffected.