Lesson 6 To show that Manganese (IV) Oxide catalyses

• Method to test Manganese (IV) oxide catalyses the decomposition of hydrogen peroxide

  1. Measure 25cm³ of hydrogen peroxide into a beaker.

  2. Place manganese (IV) oxide on filter paper and record the mass.

  3. Add manganese (IV) oxide to hydrogen peroxide, avoiding spills.

  4. Filter mixture through the same paper, ensuring oxide is captured.

  5. Let paper with oxide dry for 10-15 minutes.

  6. Label a dish, place paper and oxide inside, store in fume cupboard.

  7. Next week, remove paper, weigh; masses should match.
• A catalyst is:  A chemical that speeds up a reaction and remains unchanged at the end of the reaction.
• 1. What happens to the mass of the manganese (IV) oxide?

  Stays the same.
• 1. What happens to the appearance of the manganese (IV) oxide?

  Stays the same.
• 1. Do you think that the manganese (IV) oxide has changed chemically?

  No, it is exactly the same as it was at the start.
• Which chemical releases oxygen?

  Hydrogen peroxide
• Name the black solid used in the experiment.

  Manganese dioxide/manganese (IV) oxide
• Name the gas made in the experiment.  How would you test for this gas? 

  Oxygen. Insert a glowing splint into the gas. The splint will relight.
• After filtering what was left in the conical flask? 

  Water
• 1. Complete the sentence: – A catalyst is a substance that speeds up a chemical reaction but at the end of the reaction is left chemically unchanged.
• The hydrogen peroxide decomposes.  What does decomposition mean? 

   It breaks down into two or more simpler chemicals
• Is decomposition a physical or chemical change? 

        A chemical change.