Which of the following substances can be used as a catalyst to speed up the decomposition of hydrogen peroxide (H_2O_2)?

• A. Sodium chloride (NaCl)
• B. Glucose (C_6H_{12}O_6)
• C. Manganese dioxide (MnO_2)
• D. Calcium carbonate (CaCO_3)

Answer: (C)

Verified step by step guidance

1. Understand that a catalyst is a substance that increases the rate of a chemical reaction without being consumed in the process.
2. Recognize that the decomposition of hydrogen peroxide (H_2O_2) is a reaction that can be catalyzed by certain substances to produce water and oxygen gas.
3. Recall that manganese dioxide (MnO_2) is a well-known catalyst for the decomposition of hydrogen peroxide because it provides a surface that lowers the activation energy of the reaction.
4. Evaluate the other substances: Sodium chloride (NaCl), glucose (C_6H_{12}O_6), and calcium carbonate (CaCO_3) do not have catalytic properties for this reaction and typically do not speed up the decomposition of H_2O_2.
5. Conclude that manganese dioxide (MnO_2) is the correct catalyst to use for speeding up the decomposition of hydrogen peroxide.