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Science 9 – Chemistry Unit Name: ______________________________ Date: __________________ Block: ______ LAB – Observing Changes in Matter Physical and Chemical Changes Excellent A Data Collection Discussion Questions Conclusion B Proficient C+ Adequate C C- Not Yet Meeting I All required elements are included in the assignment. Most required elements are included in the assignment. Some required elements are incomplete OR inaccurate. Several required elements were missing OR inaccurate. - Properties of reactants - Description of change - Determine if reaction was a chemical or physical reaction - Reason why you chose physical or chemical Students can accurately answer all questions. - Properties of reactants - Description of change - Determine if reaction was a chemical or physical reaction - Reason why you chose physical or chemical Students can accurately answer most questions. Students have accurately completed the entire conclusion. Students have accurately completed much of the conclusion. - Properties of reactants - Description of change - Determine if reaction was a chemical or physical reaction - Reason why you chose physical or chemical Students can answer some of the questions accurately. Students have accurately completed some of the conclusion. - Properties of reactants - Description of change - Determine if reaction was a chemical or physical reaction - Reason why you chose physical or chemical Students have not accurately answered the questions. Student has not completed the conclusion. Purpose: to investigate the differences between physical and chemical reactions Background: In this lab, you will carry out 6 different experiments and record the information into the data table found in the Data/Observations section. Record the properties of the reactants before doing the reaction. Remember, safety first! There is acid being used. Safety goggles and lab aprons are a must! Reaction 1 Materials: Test Tube Calcium Chloride Water Graduated cylinder Procedure: 1. Put 1 small scoop of calcium chloride in the bottom of the test tube. 2. Hold the test tube at the bottom, and fill the test tube with 5 mL of water. Take note of what you feel at the bottom of the test tube. Clean-Up 1. Pour the calcium chloride solution down the sink, using lots of water to rinse it down. 2. Rinse out the test tube, using a cleaning brush to clean it out. 3. Put the test tube back into the test tube rack. Reaction 2 Materials: Steel wool Magnesium ribbon Dilute hydrochloric acid (0.5-1.0 M HCl) Test tube 50 mL beaker Please find the procedure on the next page of this lab. Procedure: 1. With the steel wool, polish a piece of magnesium ribbon. Examine it. 2. Pour dilute hydrochloric acid into a test tube to a depth of about 4 cm. Remember to pour the acid from the stock into your own beaker (20 mL or enough to cover the magnesium strip). 3. Add the magnesium ribbon to the test tube. Clean-Up 1. Pour the solution of hydrochloric acid down the sink, using lots of water to rinse it down. Make sure that you don’t pour the magnesium strip down the sink. 2. Throw the magnesium strip that is left into the garbage & rinse hands off. Reaction 3 Materials: Sodium carbonate solution Calcium chloride solution Two test tubes Two 50 mL beakers Procedure: 1. Fill one test tube half way with sodium carbonate 2. Pour 10 mL of calcium chloride solution into a second 50 mL beaker. 3. Carefully pour 10 mL of calcium chloride to the sodium carbonate test tube. Clean-Up 1. Pour the sodium carbonate + calcium chloride solution down the sink, using lots of water to rinse it down. 2. Rinse out the beaker, using a cleaning brush to clean it out. Reaction 4 Materials: Test tube Milk Acetic acid (Vinegar) Procedure: 1. Fill one test tube up half full with milk. 2. Add 10 mL of vinegar to the test tube with the milk in it. Clean-Up 1. Pour the milk + vinegar solution down the sink, using lots of water to rinse it down. 2. Rinse out the beaker, using a cleaning brush to clean it out. Reaction 5 Materials: Beaker Scoopula Sodium bicarbonate Water Procedure: 1. Place one scoop of sodium bicarbonate into the beaker. 2. Add 100 ml water to the beaker. 3. Stir for 1 minute. Clean-Up 1. Pour the sodium bicarbonate + water down the sink, using lots of water to rinse it down. 2. Rinse out the beaker, using a cleaning brush to clean it out. 2 Reaction 6 Materials: Sodium bicarbonate Acetic acid (vinegar) 2 Test tubes Two 50 ml beakers Procedure: 1. Place one scoop of sodium bicarbonate into a test tube. 2. Fill the second test tube about ¼ full with vinegar. 3. Pour the vinegar into the test tube containing sodium bicarbonate. Clean-Up 1. Pour the sodium bicarbonate + acetic acid solution down the sink, using lots of water to rinse it down. 2. Rinse out the beaker, using a cleaning brush to clean it out. Data/Observations: Reaction Properties of Starting Materials (Reactants) Detailed Description Calcium Chloride - Description of Change (Observations of Products) Physical or Chemical Indication for Chemical Change 1 Calcium chloride + water Water – Magnesium 2 Magnesium + Hydrochloric acid (HCl) HCl Sodium carbonate - 3 Sodium carbonate + calcium chloride calcium chloride – Milk 4 Milk + acetic acid (vinegar) Acetic acid – Sodium bicarbonate 5 Sodium bicarbonate + water Water Sodium bicarbonate - 6 Sodium bicarbonate + acetic acid (vinegar) Acetic acid – 3 Discussion Questions: 1. Define physical change. 2. Define chemical change. 3. Name five indicators that suggest a chemical change has occurred. a. ___________________________________________________________ b. ___________________________________________________________ c. ___________________________________________________________ d. ___________________________________________________________ e. ___________________________________________________________ 4. a. How can you tell if a temperature change has occurred if you do not have a thermometer? ______________ b. In which reaction(s) was there a temperature change? ____________________ 5. In reaction #3, the products of this chemical reaction are calcium carbonate and sodium chloride. Write a word equation for this reaction. (hint: where would you find the reactants?) ____ ____ _________________________________________ Conclusion: In this experiment, the differences between _________________ __ and _______ changes were observed. A physical change has occurred when . A chemical change has occurred when . A good example of a physical change is when and a good example of a chemical change is when ______________ ______________ . 4