Lab Report for Experiment #4
Physical and Chemical Properties and Changes
Student's Name __________ __________
Date of Experiment ___ _________
Date Report Submitted _________________

Title: (copy from lab, 1 point)
Purpose: (copy from lab, 1 point)
Changes to the Procedure by Instructors: 1. Do not test the odor of the samples. 2. In this lab the test tubes can get very dirty and cleaning is difficult. Your test tube may break, but don’t worry about it you will not need them again this term. Dispose carefully in the trash.
Have you made any changes to the procedure? Please explain:

Fill out the data sheet (page 3) for the experiment and answer the questions.
Note: read the lab introduction for clarification on the difference between physical and chemical changes. Remember that a physical change often occurs during a chemical change, but a chemical change does not always happen when a physical change occurs. If you still have questions ask your instructor. From experiment # 1 we learned that a chemical change results in a color change, the formation of bubbles, the formation of a precipitate, or a change of temperature. Keep that in mind when you are deciding whether a physical or chemical change has occurred.
Data Table (8 points)
Read carefully before you begin your experiment!
Be complete when writing your observations. One word observations are not usually complete. If there is a color change, include the color before and after. For example, silver to black. A color change is not always a chemical change. It may simply be a dilution. For example, if the color changes from blue to lighter blue after the addition of water, it is not a chemical change but a dilution. Be sure to describe the color change carefully.
Describe what you see in concise detail without forming a conclusion. Do not write conclusions instead of observations. Know the difference between an observation and a conclusion.
When you write “dissolved” that is a conclusion, you should instead write that the crystals disappeared. The word “dilution” is also a conclusion. You should instead write that the color became lighter.
Be concise but complete with your observations! If you see no change at all, you may write NVC. This means “no visible change, physical or chemical.”
The data table is on the following page.

DATA TABLE Substance Name | Color | Effect of Heat | Cold H20 | Hot H20 | LitmusTest | Dilute HCl | DiluteNaOH | Mgmagnesium | | | | | | | | CuCopper | | | | | | | | ZnZinc | | | | | | | | MgOmagnesium oxide | | | | | | | | CuC03copper II carbonate | | | | | | | | Cu(N03)2copper II nitrate | | | | | | | | NaClSodium chloride | | | | | | | |
Questions: (7 points) 1. List all the physical changes you observed. Explain why you think these changes are physical changes only and not chemical changes. (Add more boxes if needed)

Test | Observed Changed | Why I think this is a Physical Change only? | Ex. NaCl + hot water | The white crystals disappeared completely. | No bubbles appeared and there was no color change. I think that if you boil away the water, the NaCl crystals will be back. | | | | | | | | | |

2. List all the chemical changes you observed. Explain why you think these changes are chemical changes. (Add more boxes if needed).

Test | Observed Changed | Why I think this is a Chemical Change? | Mg and HCl | When Mg was added to HCl, vigorous bubbling occurred, the Mg disappeared, and the test tube was warm. | The formation of bubbles and heat indicate a chemical change. | | | | | | | | | |

3. We tested many solutions with blue and pink litmus paper. If a drop of the solution turns the blue litmus paper pink, what does it say about the solution? If a drop of a solution turns the pink litmus paper blue, what does it say about the solution? Are these changes in the litmus paper physical or chemical changes? Why do you think that? 4. When a compound melts, is that a physical change or a chemical change? Please explain. Ice will melt at 0oC. Is that a physical property or a chemical property? Please explain. 5. All the elements we tested in this experiment are metals. From your observations, is it possible to identify a substance as a metal? 6. This experiment shows that the physical and chemical properties of an element are very different from the physical and chemical properties of compounds made from the element. Compare the test results of the copper metal and the copper compounds. List three differences in the results.

Test result | Observation with Cu | Observation with Cu(NO3)2 | Observation with CuCO3 | color | | | | | | | | | | | |

7. Copy the names and the formulas of the elements and compounds from the materials list in the procedure.
Conclusion: (3 points). Answer all questions!
Write, in paragraph form with complete sentences, a statement of what you learned from this lab. Did you accomplish the purpose (restate it here)? What might you do differently if you were to repeat this experiment?
What can you conclude after performing this experiment? Your conclusion should be based on your observations during the experiment. Conclusions should be written in your best formal English, using complete sentences, paragraphs, and correct spelling. Be sure to include the definition of a physical property and a chemical property and a physical change and a chemical change. How are physical and chemical changes important in your life? Please explain.