1. Work area, safety goggles Clean your work area thoroughly, put away all books and papers, and wear safety glasses. These will minimize the possibility that an unfortunate circumstance later will result in a serious injury.

2. The test tube Carefully select a test tube with a lip, a safety precaution that prevents the test tube from falling through a utility clamp. Do NOT use a culture tube. Select a test tube that is free of defects, especially in the bottom half. We do not want a hairline crack in the bottom to widen while heating potassium chlorate over a flame.

3. Cleaning the test tube Wash the test tube with soap and water, then rinse several times with water. Many impurities normally found in the lab will form a potentially explosive mixture with potassium chlorate so a thorough cleaning is required.

4. Hairline cracks Look the test tube over carefully and discard it if any cracks can be seen in the bottom half of the tube. Hairline cracks that are not apparent at first, are noticeable after a thorough cleaning. Such cracks could lead to serious complications later.

5. Drying the test tube Flame the test tube dry. Do NOT use paper towel. Bits of towel will probably react explosively with the chlorate when heated, so the test tube should be flame-dried.

6. Cooling Wait for the test tube to cool before using. Accidents are likely when you handle hot glassware containing hazardous chemicals.

7. Adding the MnO₂ Get a pinch of MnO₂ and place it in the cooled test tube and weigh. Be careful not to spill the MnO₂. In case of spillage, wash area with a sponge and plenty of water. Do not inhale the MnO₂ since its dust is highly toxic. When removing MnO₂ from the container or inserting it into the test tube, tilt the bottle or test tube to reduce the likelihood of spillage.

8. Adding the KClO_X Have your teacher show you how to add the potassium chlorate, then add it. Close the cover on the potassium chlorate bottle. Chlorates will react unpredictably when wet. If the bottle is open to moisture in the air, the likelihood of explosion when the bottle is moved is increased. Immediately notify the teacher of any spillage. Serious accidents occur when spillage is not promptly attended to.

9. Determining the mass Zero the balance with a beaker on it so that the test tube may be placed securely in the beaker on the balance. Weight the test tube with MnO₂ and potassium chlorate.

10. The ring stand set up Attach the test tube at a 45° angle to a ring stand using a utility clamp. Be sure the pole is tightly screwed into the base of the ring stand. Be sure the utility clamp is clamped securely around the test tube. The utility clamp must be entirely metal. Any plastic will melt and subsequently ruin our experiment. The 45° angle helps you to notice if a lot of energy is collecting in the chemicals in the test tube. If the test tube is vertical, the contents may absorb a lot of heat energy before you will be able to notice it. There is greater likelihood that the contents of the test tube will come flying out suddenly if the test tube is vertical rather than at 45°. Since there is a reasonable possibility that you might drive the chlorate out of the tube despite these precautions, do not aim the test tube at anyone.

11. Heating the solid chlorate Heat the test tube GENTLY for a few minutes, holding the burner in your hand, moving the flame around, and gradually ease the potassium chlorate into melting. When the chlorate is solid, it is most difficult to keep in the test tube. If you heat the bottom, you run the risk of vaporizing the oxygen underneath while the solid chlorate sits on top of it. The oxygen will seek to expand about a thousand times its original volume (in the chlorate) and will surely drive anything above it out of the test tube. So heat gently, moving the flame around and ease the edges of the chlorate into melting.

12. Heating the melted chlorate Once the chlorate is melted, heat more strongly, but cautiously, keeping the chlorate reacting, yet not letting it climb more than half way up the test tube. Once the chlorate is melted, it is easier to control, yet it is extremely dangerous if it does contact a reducing agent such as a piece of paper, wood, or skin. Continue to hold the burner in your hand, so that if the chlorate reacts too violently, you are able to remove the heat immediately.

13. Decomposition Continue heating until the chlorate completely decomposes into potassium chloride and oxygen. The potassium chloride can be seen since it is a solid. It is strange to see a liquid turn into a solid as the result of heating, yet this is exactly what will happen. However the substances are different and have very different melting and boiling points. Oxygen gas will form and can be seen leaving the test tube.

14. Heating the KCl Once the transformation in 13 is accomplished, the chemicals are no longer explosive and the test tube should be heated strongly for several minutes to drive out any oxygen trapped inside the crystal. You no longer need to hold the burner. Remember, for the reaction to be safe enough to be heated strongly, the solid must have been formed as the result of heating. If you took the flame away in part 13 and the substance solidified, you probably just allowed the potassium chlorate to cool. In this case, you are back in part 11 with a very dangerous reactant.

15. After heating After thorough, strong heating, let the test tube and contents cool and weight them. Wash the test tube with water. The KCl mixed with MnO₂ is a harmless mixture (not edible or inhalable!). It may be washed down the sink.

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