Answer:
The correct answer is because MnO2 accelerates decomposition.
Step-by-step explanation:
Manganese dioxide acts as a catalyst in the decomposition of hydrogen peroxide (H2O2), thus accelerating its decomposition.
Catalysts accelerate the speed of reactions by lowering the activation energy barrier between reagents and products.
As oxygenated water breaks down, oxygen is released faster when MgO2 is present as a catalyst in the reaction.
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