Lesson 5 of 6 · Reaction Rates
Experiment⭐ 30 XP🧪 Potion KitchenCatalysts and Enzymes
Reaction Rates.
🎯 Your mission
Predict it first. Then prove yourself right (or wrong).
⚡ The twist
Mixing two safe things doesn't always make a safe thing.
Mind = Blown
💧 Hot water can freeze faster than cold water under the right conditions. Nobody fully understands why.
Make a hypothesis first
Predict: will the mixture get hotter, colder, or stay the same?
What You'll Learn
A catalyst provides an alternative pathway with lower activation energy, so more collisions succeed. It is not consumed and can be recovered unchanged. Enzymes are biological catalysts, exquisitely specific and easily denatured by heat or extreme pH.
Key Words
Tap a word to see its definition.
Materials Needed
- hydrogen peroxide solution
- manganese dioxide
- raw liver
- boiled liver
- gas syringe
- conical flask
- gloves
Safety First
- Hydrogen peroxide bleaches skin and damages eyes — goggles and gloves throughout.
- Raw liver carries bacteria: keep it off skin, use tongs, and wash hands and surfaces thoroughly.
Steps
Read the explanation above and note the two key terms before you start.
Decompose hydrogen peroxide with manganese dioxide, then with a piece of raw liver, then with liver that has been boiled. Compare gas produced in each and explain the boiled result.
Record what actually happened, including anything that did not match what you expected.
Write a conclusion that answers the question this lesson opened with, and state your uncertainty.
Check Your Understanding
Question 1
1 of 2A catalyst speeds a reaction by:
Where you see this in real life
Your toothpaste, your soap, even your breakfast involves this.
Stretch Challenge
Try this in real life this week.
Ask a grown-up to help you mix two safe kitchen things. Predict what will happen first.
For the dinner table
“What's something we cook that mixes things together this way?”
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Catalysts and Enzymes
Predict it first. Then prove yourself right (or wrong).
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