Chemistry Nov. 12 & 13, 2015

OBJECTIVE: Students will complete a lab activity and write a report classifying various reactions as either a physical or chemical change.

W.O.D. Slander-a false statement to damage the reputation of another

WARM-UP
1. Obtain a copy of the lab handout, read it completely so that you are clear on what must be done.
2. List 4 clues that indicate that a chemical change has taken place.


HW
Complete the lab report

CW

Identifying physical and chemical changes

Aim:

Materials:

Procedure:

1.     Add the copper chloride powder to the beaker.

2.     Place 25ml of water to the powder in the beaker. Do not stir. Measure the temperature of the mixture. Record observations.

3.     Stir the mixture and check the temperature of the stirred mixture. Record observations.

4.     Loosely roll the piece of aluminum foil and place it into the copper chloride solution. Record all observations until the aluminum is completely reacted.

5.     Rinse the beaker making sure no aluminum goes into the sink..

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6.     Obtain a piece of magnesium ribbon from the teacher. Tear it into halves.

7.     Using a pair of tongs hold one piece of the magnesium ribbon into blue flame of a Bunsen burner. Record observations.

8.     Place the other piece of magnesium into a test-tube. Add several drops of 6M hydrochloric acid. Record all observations (CAUTION IN HANDLING 6M HYDROCHLORIC ACID.)

9.     After all of the metal has reacted, rinse the test-tube with plenty running water.

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10.                       Place several crystal of copper sulfate into a mortar and crush the solid into a powder using the pestle.

11.                       Add a 10 g of the crushed powder to a DRY TEST-TUBE and heat for 3-4 minutes or until the color of the solid has changed completely. (CAUTION HEATING SUBSTANCES) Record observations. Place the hot test-tube in a test-tube rack to cool.

12.                       Place a thermometer into the cool test-tube record the temperature. Add several drops of water to the solid. Record your observations.

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13.                       Place 5g of sodium bicarbonate into a test-tube.

14.                       Add several drops of 6M hydrochloric acid to the sodium bicarbonate. Record all observations.

Results/Data collection/Observations

Use a table to record your results (see the board)

Conclusion

1.     What is a physical change? Give 2 examples from your results.

2.     What is a chemical change Give 3 examples from your results.

3.     List 3 observations made in this lab.

4.     Make inferences from 2 of the observations listed in #3

5.     There are 4 main clues that a chemical change is occurring. Show where in your results did you see any of these clues.