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In your composition notebook, neatly write the title of this experiment, your name, the date, data/observations, calculations, and responses to post-lab questions

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In your composition notebook, neatly write the title of this experiment, your name, the date, data/observations, calculations, and responses to post-lab questions. Use headings to organize your work. Then take photos of your written pages, required photos of any experimental set-ups, and turn them into a single pdf file. (Use an app like CamScanner, Adobe Scan, or Simple Scanner to do so.) Then upload the pdf into this assignment.

Cabbage Juice Indicator and Acid-Base Chemistry Background In this experiment, you will extract the pigment molecules from red cabbage and observe their colors when you expose them to acidic, basic and neutral solutions. Red cabbage leaves contain several pigment molecules (called anthocyanins) that are pH indicators. A pH indicator is a substance that changes color based on the level of acidity (pH) of its environment. Depending on the acidity level (pH) of the environment that cabbage juice pigments are exposed to, their structures change. Shown below are the structural changes that a particular red cabbage pigment undergoes with changes in pH. Note that the color of each species is indicated. Materials Needed: • red cabbage (Just a few leaves will suffice.) • citrus juice (a few mL of lemon, orange, or grapefruit juice) • vinegar • baking soda • at least one of the following: isopropanol (rubbing alcohol), ammonia cleaning solution • five small containers that are the same size (shot glasses, bowls, Tupperware, juice glasses) Notes for Submission Please write this lab in your composition book. Copy down and complete any tables provided. Note any observations, and include responses to questions. Use headings to organize the different sections of the lab. Take photos of lab materials as directed, as well as photos of your written pages. Turn all of these images into a single pdf file, and upload that single file into the Canvas assignment for this lab. 1 Procedure 1. Tear a few leaves of red cabbage into pieces that are about 2 in x 2 in. 2. Add these cabbage-leaf pieces to two cups of water in a pot, and then heat on the stove. 3. Bring the mixture to a boil, and then boil gently for 10 minutes or until the water turns deep purple. 4. Turn off the heat, and allow the mixture to cool to room temperature. 5. Remove the leaves from the solution by pouring off the solution into a separate container. Use a strainer if needed. 6. Add a small amount of your cabbage juice to each of five small containers that are all about the same size. 7. Do not add anything besides cabbage juice to the first container. This is your cabbage juice control. Note your observations in a data table like the one shown below. Save this sample for comparison to the others. 8. To the second container that has cabbage juice in it, add some citrus juice (lemon, orange, or grapefruit) until you see a color change. Stir as needed. Note your observations in your data table. Save this sample for comparison to the others. 9. To the third container that has cabbage juice in it, add some vinegar until you see a color change. Stir as needed. Note your observations in your data table. Save this sample for comparison to the others. 10. To the fourth container that has cabbage juice in it, add some baking soda until you see a color change. Stir as needed. Note your observations in your data table. Save this sample for comparison to the others. 11. To the fifth container that has cabbage juice in it, add some rubbing alcohol or ammonia cleaning solution until you see a color change. Stir as needed. Note your observations in your data table. Save this sample for comparison to the others. 12. Take a selfie photo with your five samples. Include this photo with your submission. Sample Observations (color) 1 cabbage juice (nothing added) 2 cabbage juice with citrus juice added 3 cabbage juice with vinegar added 4 cabbage juice with baking soda added 5 cabbage juice with rubbing alcohol or ammonia cleaning solution added 2 Post-Lab Questions 1. Based on the color that you observed for each sample, determine the approximate pH of the sample, and draw the structure of the pigment that was present (most abundant) in that sample. If, based on the color, you think that the solution contains a mixture of two pigments, draw both structures. (Refer to the structures and information provided in the Background section of this lab.) Please organize your responses in a table like the one shown below. Sample Color Approximate pH Structure(s) of Pigment(s) Present 1 cabbage juice (nothing added) 2 cabbage juice with citrus juice added 3 cabbage juice with vinegar added 4 cabbage juice with baking soda added 5 cabbage juice with rubbing alcohol or ammonia cleaning solution added 3 2. Take a look at the transformation of the “dark purple” pigment structure into the “green” pigment structure. a. If we call the dark purple pigment the acid, what should we call the green pigment? b. What exactly does the dark purple pigment have to do to transform into the green pigment? c. Why does it make sense that this transformation occurs when you raise the pH? 3. What is a pH indicator? Why are pH indicators useful? Suggest an everyday application that would use a pH indicator. 4 Cabbage Juice Indicator and Acid-Base Chemistry Background In this experiment, you will extract the pigment molecules from red cabbage and observe their colors when you expose them to acidic, basic and neutral solutions. Red cabbage leaves contain several pigment molecules (called anthocyanins) that are pH indicators. A pH indicator is a substance that changes color based on the level of acidity (pH) of its environment. Depending on the acidity level (pH) of the environment that cabbage juice pigments are exposed to, their structures change. Shown below are the structural changes that a particular red cabbage pigment undergoes with changes in pH. Note that the color of each species is indicated. Materials Needed: • red cabbage (Just a few leaves will suffice.) • citrus juice (a few mL of lemon, orange, or grapefruit juice) • vinegar • baking soda • at least one of the following: isopropanol (rubbing alcohol), ammonia cleaning solution • five small containers that are the same size (shot glasses, bowls, Tupperware, juice glasses) Notes for Submission Please write this lab in your composition book. Copy down and complete any tables provided. Note any observations, and include responses to questions. Use headings to organize the different sections of the lab. Take photos of lab materials as directed, as well as photos of your written pages. Turn all of these images into a single pdf file, and upload that single file into the Canvas assignment for this lab. 1 Procedure 1. Tear a few leaves of red cabbage into pieces that are about 2 in x 2 in. 2. Add these cabbage-leaf pieces to two cups of water in a pot, and then heat on the stove. 3. Bring the mixture to a boil, and then boil gently for 10 minutes or until the water turns deep purple. 4. Turn off the heat, and allow the mixture to cool to room temperature. 5. Remove the leaves from the solution by pouring off the solution into a separate container. Use a strainer if needed. 6. Add a small amount of your cabbage juice to each of five small containers that are all about the same size. 7. Do not add anything besides cabbage juice to the first container. This is your cabbage juice control. Note your observations in a data table like the one shown below. Save this sample for comparison to the others. 8. To the second container that has cabbage juice in it, add some citrus juice (lemon, orange, or grapefruit) until you see a color change. Stir as needed. Note your observations in your data table. Save this sample for comparison to the others. 9. To the third container that has cabbage juice in it, add some vinegar until you see a color change. Stir as needed. Note your observations in your data table. Save this sample for comparison to the others. 10. To the fourth container that has cabbage juice in it, add some baking soda until you see a color change. Stir as needed. Note your observations in your data table. Save this sample for comparison to the others. 11. To the fifth container that has cabbage juice in it, add some rubbing alcohol or ammonia cleaning solution until you see a color change. Stir as needed. Note your observations in your data table. Save this sample for comparison to the others. 12. Take a selfie photo with your five samples. Include this photo with your submission. Sample Observations (color) 1 cabbage juice (nothing added) 2 cabbage juice with citrus juice added 3 cabbage juice with vinegar added 4 cabbage juice with baking soda added 5 cabbage juice with rubbing alcohol or ammonia cleaning solution added 2 Post-Lab Questions 1. Based on the color that you observed for each sample, determine the approximate pH of the sample, and draw the structure of the pigment that was present (most abundant) in that sample. If, based on the color, you think that the solution contains a mixture of two pigments, draw both structures. (Refer to the structures and information provided in the Background section of this lab.) Please organize your responses in a table like the one shown below. Sample Color Approximate pH Structure(s) of Pigment(s) Present 1 cabbage juice (nothing added) 2 cabbage juice with citrus juice added 3 cabbage juice with vinegar added 4 cabbage juice with baking soda added 5 cabbage juice with rubbing alcohol or ammonia cleaning solution added 3 2. Take a look at the transformation of the “dark purple” pigment structure into the “green” pigment structure. a. If we call the dark purple pigment the acid, what should we call the green pigment? b. What exactly does the dark purple pigment have to do to transform into the green pigment? c. Why does it make sense that this transformation occurs when you raise the pH? 3. What is a pH indicator? Why are pH indicators useful? Suggest an everyday application that would use a pH indicator.