Goggles & Lab Coats



Name __________________________________

Chapter 13 – Matter

Physical & Chemical Changes

Background Information

How can you detect a physical change? Just look to see whether or not the matter has changed size, shape, or form (state of matter). The four most common changes of state are condensation, freezing, melting, and evaporation. A type of matter can change to a different form and still be the same type of matter. For example, adding salt to water changes the boiling and freezing point, but it is still water and salt. Boiling water changes the state, but it is still

H2O. Chemical changes are going on around you every day. You know that a chemical change occurs because you can see that a new substance forms. Some signs of a chemical change are: a release of energy when something burns and heat is given off, an energy change when something rusts, a color change, or fizzing and bubbles when a gas is given off.

Question

How can I identify a physical change from a chemical change?

Hypothesis

I think that _________________________________________________________

Equipment

Triple beam balance

Cardboard 8 ½ ” x 11”

1 – 2 liter soda bottle

Funnel

1 T. baking soda

3 T. vinegar

Balloon

Pencil

Procedure

1. Measure the mass of the cardboard. Record the mass in the DATA TABLE.

2. Tear the cardboard into smaller pieces. Measure the mass of the cardboard pieces. Record the mass in the DATA TABLE.

DATA TABLE PHYSICAL CHANGE

| |MASS (g.) |

|Cardboard (1 piece) | |

|Cardboard (smaller pieces) | |

Procedure

1. Pour the vinegar into the bottle.

2. Use the funnel and pour the baking soda into the balloon.

3. Carefully place the balloon onto the mouth of the soda bottle, being careful NOT to mix the baking soda into the vinegar yet.

4. Measure the mass of the soda bottle and balloon. Record the mass in the DATA TABLE.

5. Lift the balloon to mix the baking soda with the vinegar in the bottle. DO NOT remove the balloon. Wait for the reaction.

6. Measure the mass of the bottle and balloon. Record the mass in the DATA TABLE.

7. Release the balloon from the soda bottle. Measure the mass of the bottle and balloon. Record the mass in the DATA TABLE.

DATA TABLE CHEMICAL CHANGE

| |Mass (g.) |

|Bottle w/ balloon (unmixed) | |

|Bottle with balloon (mixed) | |

|Bottle – remove balloon (mixed) | |

Analysis

1. What evidence of chemical change did you observe? Explain.

2. Is it always easy to tell whether or not energy is released? _____ YES _____NO

Give an example of a chemical change that does not show an obvious energy change.

Conclusion

I learned that __________________________________________________________

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