LAB 9A: TEMPERATURE AND HEAT, PART A

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1 Name: Period: LAB 9A: TEMPERATURE AND HEAT, PART A Hot and cold are familiar sensations. What happens when something hot comes in contact with something cold? Think about putting some ice cubes in a drink. Things don t remain the same. Changes occur and these changes have to do with the movement of energy from one material to the other. This investigation will explore the difference between temperature and thermal energy. Question How are temperature and thermal energy related? Part A. Mixing Hot and Cold Water Hypothesis Suppose you mix equal masses of water. As an example, one sample is at 0 C and the other is at 50 C. What do you think the final temperature of the mixture will be? Write a hypothesis that answers this question. Variables Manipulated variable: Responding variable: Controlled variables (at least 3): Materials Temperature probe Data collector Electronic balance Aluminum cube 3 12-oz foam cups Ice Hot water Tongs 100 ml graduated cylinder Safety goggles Procedure 1. You will need three 12 ounce foam cups for this experiment. Label two of the cups as follows: HOT and COLD. 2. Prepare an ice bath by filling the unlabeled cup half with ice and the rest of the way with liquid water. 3. Connect the temperature probe to the Data Collector and select Meter mode for this experiment. 4. Use a graduated cylinder to measure 100 ml of very hot tap water. Pour the hot water into HOT cup. 5. Use a graduated cylinder to measure 100 ml of the ice water (do not include ice cubes). Pour the cold water into the COLD cup. 6. Place the temperature probe into the COLD cup, wait until the reading stabilizes and record the temperature in Table Place the temperature probe into the HOT cup. Wait until the reading stabilizes and record the temperature in Table Immediately pour the hot water into the cold water. This is the mixture. 9. Stir well using the temperature probe and measure the final temperature (when it has stabilized). Record your data in Table Discard the hot and cold water in labeled cups. Do not throw away your ice water bath. You will be using it again in the second part of the investigation.

2 Data Table 1: Temperature data for mixing equal masses of water Cold water temperature ( C) Hot water temperature ( C) Mixture temperature ( C) Analysis 1. Compose a graph comparing temperature data for mixing equal masses of water. Be sure to include all the parts of a complete graph. 2. Are the results what you expected (within 3 degrees)? Why or why not? 3. How do you think your results would have been different if you had used more hot water than cold water, instead of equal masses?

3 Name: Period: LAB 9A: TEMPERATURE AND HEAT, PART B In Part A of this lab, you were guided through an investigation relating temperature and thermal energy. In Part B, you will be designing your own investigation with the same question in mind. However, instead of mixing equal quantities of hot and cold water you will be mixing equal quantities of hot aluminum and cold water. Question How are temperature and thermal energy related? Part B. Combining Hot Metal and Cold Water Hypothesis Suppose you mix equal masses of cold water and hot metal. Will the final temperature follow the same pattern as the experiment you did in Part 1? Write a hypothesis that answers this question. Variables Manipulated variable: Responding variable: Controlled variables (at least 3): Procedure Design a procedure for an investigation that tests the hypothesis above. Remember to include the following components: numbered list, clear and simple instructions for each step, an indication of what is being measured, and an indication of what measurements are being recorded. You must have a complete procedure before beginning data collection.

4 Procedure, continued: Data Design a data table to use during this investigation. Remember to include the following components: multiple columns and rows, column headings should have labels with units, and title. You must have a complete data table before beginning data collection. Analysis Compose a graph comparing appropriate data. Be sure to include all the parts of a complete graph.

5 Write separate paragraphs, which answer questions below. This is part of the analysis. Paragraph 1: 1. Compare the results of this investigation (Part B) to the results of Part A where equal volumes of water were mixed. 2. Explain why the results from Part A were the same or different from Part B. Paragraph 2: 1. Explain what is happening between the aluminum cube and water in terms of temperature and energy. 2. How much energy does it take to raise the temperature of one gram of aluminum by 1 C compared to raising the temperature of one gram of water by 1 C? (Look up these values. This physical property is called specific heat.) Relate your answer back to your experimental results. 3. Thermal energy and temperature are related, but they are not the same thing. According to your results, what does the concept of heat energy (or thermal energy) take into account that temperature does not?

6 Conclusion Write a conclusion using the format from the document A Recipe for a Good Conclusion, which is in your science notebook. Once all parts of the investigation are complete, you will be writing a formal lab report that will be graded as a semester project.