Hydrogen peroxide can decompose in the presence of which of the following substances?

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

Answer: (C)

Verified step by step guidance

1. Understand that hydrogen peroxide (H_2O_2) decomposes into water and oxygen gas, but this reaction is usually slow without a catalyst.
2. Recognize that a catalyst is a substance that speeds up a chemical reaction without being consumed in the process.
3. Identify which substances among the options are known catalysts for the decomposition of hydrogen peroxide. Manganese dioxide (MnO_2) is a well-known catalyst that accelerates this reaction.
4. Note that sodium chloride (NaCl), calcium carbonate (CaCO_3), and glucose (C_6H_{12}O_6) do not act as catalysts for this decomposition and therefore do not speed up the reaction.
5. Conclude that the presence of manganese dioxide (MnO_2) facilitates the rapid decomposition of hydrogen peroxide by providing an alternative reaction pathway with lower activation energy.