Statement-I: Oxygen gas is easily produced at a faster rate by heating

Statement-I: Oxygen gas is easily produced at a faster rate by heating a mixture of potassium chlorate and manganese dioxide than heating potassium chlorate alone.
Statement-II: Manganese dioxide acts as a negative catalyst.

Both the statements are individually true and Statement II is the correct explanation of Statement I
Both the statements are individually true but Statement II is not the correct explanation of Statement I
Statement I is true but Statement II is false
Statement I is false but Statement II is true
This question was previously asked in
UPSC NDA-1 – 2015
The correct option is C. Statement I is true, but Statement II is false.
Statement I correctly describes the effect of adding manganese dioxide (MnO₂) to potassium chlorate (KClO₃) when heated. MnO₂ acts as a catalyst, speeding up the decomposition of KClO₃ into potassium chloride (KCl) and oxygen gas (O₂). The reaction is 2KClO₃ (s) → 2KCl (s) + 3O₂ (g).
Statement II claims that manganese dioxide acts as a negative catalyst. A negative catalyst (or inhibitor) slows down a reaction. Since MnO₂ increases the rate of decomposition of KClO₃, it is a positive catalyst.
Catalysts increase the rate of a chemical reaction without being consumed in the process. Positive catalysts increase the rate, while negative catalysts decrease it. Manganese dioxide is a common positive catalyst used in the laboratory preparation of oxygen from potassium chlorate.