Name______________________________             Date_______________

CHEMICAL CHANGE LAB

Your teacher will give you 2 test tubes labeled A (clear) and B (blue). For each test tube answer the following:

Test tube A:

1.     What does it look like?

2.     Does it have any odor?

3.     Gently shake the test tube do the contents move? What state are they in?

4.     What do you think the substance is?

_________________________________________

Test tube B:

5.     What does it look like?

6.     Does it have any odor?

7.     Gently shake the test tube do the contents move? What state are they in?

8.     What do you think the substance is?

_________________________________________

9.     Predict what would happen if you were to mix the 2 test tubes:

DO NOT MIX THE TEST TUBES UNTIL YOU ARE TOLD!

10. AFTER YOU ARE TOLD PORE TEST TUBE B (blue) INTO TEST TUBE A (clear). Describe what happens, be specific.

11. Was the change physical or chemical?

Your teacher will now give you 2 test tubes labeled C (clear) and D (blue). For each test tube answer the following:

Test tube C:

12. What does it look like?

13. Does it have any odor?

14. Gently shake the test tube do the contents move? What state are they in?

15. What do you think the substance is?

_________________________________________

Test tube D:

16. What does it look like?

17. Does it have any odor?

18. Gently shake the test tube do the contents move? What state are they in?

19. What do you think the substance is?

_________________________________________

20. Predict what would happen if you were to mix the 2 test tubes:

DO NOT MIX THE TEST TUBES UNTIL YOU ARE TOLD!

21. AFTER YOU ARE TOLD PORE TEST TUBE D (blue) INTO TEST TUBE C (clear). Describe what happens, be specific.

22. Was the change physical or chemical?

CHEMICAL - PHYSICAL CHANGE LAB (continued)

Name_________________________

The blue clear liquid in test tube D was a solution of Bromo Thymol Blue. This is an INDICATOR, which means it tells something about the chemical condition of a substance, in this case whether it is an acid or a base. This indicator turns yellow in the presence of an acid.

1.     Predict what would happen if you pored test tube D (the indicator) into test tube A (water).

2.     Predict what would happen if you pored test tube B (blue food color + water) into test tube C (dilute HCl).

Your teacher will now give you more of the indicator solution. Take a straw and GENTLY blow into the test tube.

3.     Describe what happens.

4.     What does this mean about the solution that resulted? What did your breath do to the solution?

NOTE: (for you chemists)

2CO₂ (from your breath) + H₂O (from the indicator solution) à

2HCO₃ (carbonic acid)

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NOTE FOR THE TEACHER