Infant Incubator Lesson 4
What happens when chemicals combine?
Estimated class Time:
Two 40 minute class periods
Question:
What happens when chemicals combine?
Materials:
- 100 mL 30% Hydrogen Peroxide
- 10 g Potassium Iodide
- Erlenmeyer Flask (250 mL or larger)
- Water
- Clear dish soap
- Thermometer (Infrared is best)
- Video recording device (phone, ipad, etc.)
Lesson Level Learning Objectives:
- MS-PS1-2: Develop models before, during and after substances are combined.
- Asking questions about what happens when substances are combined. (Cause and Effect)
Phenomenon:
- Students will observe a demonstration of a chemical reaction (elephant toothpaste) that has a temperature change, a production of gas, and a change in volume.
- In small groups brainstorm related phenomena (Examples may include: coke and mentos, snake fireworks, baking soda and vinegar, shaking a soda, water rocket) and explain why it is related.
- Students write new questions on the post-it notes that they have about the phenomenon and discuss and post them on a DQB in the classroom.
What we Figured Out:
- When we combined the crystals and the water, it did not change. There was not a reaction.
- When we combined the crystal water and the unknown substance it changed.
- It fizzed, bubbled and rose up.
- It changed colors.
- It got hot.
Questions we still have:
- What are the substances that were combined?
- Why does it have all of those changes?
- Why was the flask warm?
- Why did it change colors?
- How/why does it foam up?
- Why did it react slowly?
- Why did it stain skin?
- Why didn’t it stain the glass?
- Does temperature affect color?
- Does the amount of substances used matter?
- Is it foam or bubbles?
- What is foam?
- Does the foam/bubbles dissolve or evaporate?
- Where did the liquids go?
- How did the clear liquids become a yellow foam?
- Why did the crystals in water become cold?
- What would happen with more/less ingredients?