Question

q2. manganese dioxide catalyses the decomposition of hydrogen peroxide solution. oxygen and water are produced. (a) explain how a manganese dioxide catalyst increases the rate of decomposition of hydrogen peroxide. (e) fine manganese dioxide powder produces a higher rate of reaction than coarse manganese dioxide lumps. sketch on the figure above the results you would expect for student bs experiment with fine manganese dioxide powder. (f) hydrogen peroxide molecules collide with manganese dioxide particles during the reaction. why does fine manganese dioxide powder produce a higher rate of reaction than coarse manganese dioxide lumps? tick (✓) one box. fine manganese dioxide powder has a larger surface area. fine manganese dioxide powder has larger particles. fine manganese dioxide powder produces less frequent collisions.

Explanation:

(a) A catalyst like manganese dioxide provides an alternative reaction pathway with a lower activation energy. This allows more hydrogen - peroxide molecules to have sufficient energy to react, thus increasing the rate of decomposition.
(f) The surface - area - to - volume ratio affects the rate of a reaction. Fine powder has a larger surface area compared to lumps. A larger surface area means more sites for the reactant (hydrogen peroxide) to collide with the catalyst (manganese dioxide), increasing the frequency of effective collisions and the reaction rate.

Answer:

(a) Manganese dioxide provides an alternative reaction pathway with lower activation energy, increasing the number of reacting molecules and the reaction rate.
(f) Fine manganese dioxide powder has a larger surface area.