Students love spectacular chemical reactions, but do they always know what they are seeing? Use these ten targeted demonstrations to help students become proficient in identifying the five different types of chemical reactions. Single Replacement
- Stunning silver crystals completely cover a wire surface and the solution turns blue when copper wire coil is suspended in silver nitrate solution.
- Aluminum dissolves, copper metal precipitates, and things really heat up when aluminum foil is added to copper(II) chloride.
- Mixing copper(II) chloride and sodium phosphate produces a beautiful turquoise precipitate.
- An “avalanche” of snow-white precipitate suddenly appears when sodium chloride and silver nitrate are combined.
- Mix Milk of Magnesia (MOM) with universal indicator, add hydrochloric acid solution, and watch a rainbow appear and disappear as the antacid neutralizes the simulated stomach acid.
- Adding water to solid calcium oxide gives calcium hydroxide, along with enough heat to fry an egg.
- Burning steel wool provides a glowing demonstration of the exothermic combination reaction of iron and oxygen.
- Fill a Petri dish with salt and universal indicator solution, attach alligator clips and a battery, and observe a rainbow of color changes as the water molecules split apart.
- Use a “wine airlock” to identify the gas and analyze the color changes produced when solid copper(II) carbonate is heated.
- Add a little isopropyl alcohol to a soda bottle, ignite the vapors and “whoosh”! The combustion of isopropyl alcohol and oxygen creates a rush of gases and a spectacular blue flame.
Perform the demonstrations together as an introduction or as a review of reaction types, or space them over several days to focus on specific types of chemical reactions. Teacher Demonstration Notes, along with a reproducible student worksheet, are included. Concepts:
Combination reaction, combustion, decomposition, electrolysis, exothermic reaction, oxidation–reduction, precipitation reaction, single and double replacement. Time Required:
One full class period Note:
Some common laboratory equipment is required, but not provided.