In the preparation of oxygen by heating KClO3 in the presence of MnO2, only moderate heat is needed because the catalyst acts by

Answer Details

When potassium chlorate (KClO3) is heated in the presence of manganese dioxide (MnO2), oxygen gas is produced. The role of MnO2 is to act as a catalyst in the reaction, meaning that it increases the rate of the reaction without being consumed itself. In this case, the catalyst works by lowering the energy barrier of the reaction, allowing it to occur at a lower temperature than it would without the catalyst. Therefore, the correct option is "lowering the energy barrier of the reaction."