1. Warm Up: Find the density of the box below.
Mass 456 g
12.5 cm
5.6 cm
5.6 cm

2. Warm Up: Why is this picture correct? (think scientifically)

4. Chemistry Can Be Fun

5. 1.What is Chemistry?

6. Chemistry
Chemistry is the study of matter and energy and the interactions between them.

7. 2.Why do we need to know chemistry?
Because understanding chemistry helps you to understand the world around you.
Cooking is chemistry.
Most of what you can touch or taste or smell is a chemical.
When you study chemistry, you come to understand a bit about how things work.
Chemistry isn't secret knowledge, useless to anyone but a scientist. It's the explanation for everyday things, like why laundry detergent works better in hot water or how baking soda works or why not all pain relievers work equally well on a headache.
If you know some chemistry, you can make educated choices about everyday products that you use.

8. 3.What is a chemical reaction?
A chemical reaction is the change of a substance into a new one that has a different chemical identity
Typically, a chemical change is irreversible.
Examples include:
rusting of iron  
combustion (burning) of wood  
metabolism of food in the body  
cooking an egg
Baking a cake

9. 4.How can I tell if a chemical reaction is occurring?
A chemical reaction is usually accompanied by easily observed physical effects such as:
the emission of heat and light
the change of temperature
the formation of a precipitate (solid)
a gas being released
a color change (adding food color to a liquid does not count)

10. Let’s Create A Chemical Reaction

11. The Materials: Clear Container Hydrogen Peroxide (?) Dish detergent
Food Color
Packaged yeast (?)
Measuring cup
Funnel
Spoon or stirrer
Goggles
Protective Lab Coat
Pan

12. 5.What will happen when we add food coloring to the Hydrogen peroxide?
6.Have we created a new substance?
7. What happens when we add the dish detergent?
8. Have we created a new substance?

13. Next, we add the yeast
Yeast is a live, single-celled fungus. One familiar example is the beige granules that come in little paper packets. This organism lies dormant until it comes into contact with warm water. Once reactivated it releases carbon dioxide. This is what makes bread rise.
Catalyst: a substance that increases the rate of a chemical reaction without itself undergoing any permanent
chemical change.

14. The Yeast will act as our catalyst…
9. Before we add the yeast, I need a few volunteers to touch the bottle. What does it feel like? 10. What do you think will happen when we add yeast, a catalyst, to our soapy mixture?

15. The Result…
11. What happened after the yeast was added? Describe what you see? I need my volunteers to touch the bottle again, and then wash their hands. 12. What does the container feel like? What happened?

16. 13. Is this a chemical reaction. Why. What is the evidence
13. Is this a chemical reaction? Why? What is the evidence? (refer to question 4) Was a new substance formed?

17. Summary
The foam you made is special because each tiny foam bubble is filled with oxygen. The yeast acted as a catalyst (a helper) to remove the oxygen from the hydrogen peroxide. Since it did this very fast, it created lots and lots of bubbles. Did you notice the bottle got warm. Your experiment created a reaction called an Exothermic Reaction - that means it not only created foam, it created heat! The foam produced is just water, soap, and oxygen and can be cleaned up with a sponge. Pour any extra liquid left in the bottle down the drain.

18. 14. What is the Chemical Equation for our reaction?
Elephant Toothpaste Chemistry
The overall equation for this reaction is:
2 H2O2(aq) → 2 H2O(l) + O2(g)
Hydrogen Peroxide yields Water and Oxygen bubbles

19. The Law of Conservation of Mass
Established in 1789 by French Chemist
Antoine Lavoisier
States that mass is neither created nor
destroyed in any ordinary chemical reactions.
Or more simply, the mass of substances produced (products) by a chemical reaction is always equal to the mass of the reacting substances (reactants).

20. Mass of our experiment
15. If we measured the mass prior to the chemical reaction (the reactant) and compared it to the mass after the reaction (the product), what would we find?
16. Does this explain or contradict The Law of Conservation of Mass? Why?

21. Elephant toothpaste on steroids