Name: Miss Hargest



3P UNIT: Cabbage Chemistry

Objectives:

• Students will be able to investigate that properties of acidic and basic substances based on previous knowledge

• Students will be able to identify acidic and basic levels by comparing them to known colors and characteristics.

• Students will be able to create and present scientific findings using clear language, appropriate and accurate data in the form of graphs and tables when creating a lab report

• Students will be able to design and follow through an inquiry based procedure and communicate the results to the rest of the class

Class Description/ Prior Knowledge:

This unit will take place in an 11th grade chemistry class. The class is considered advanced because students have already taken a general physical science class in 10th grade. Students should have gained a basic and general knowledge of chemistry in the 10th grade class so in this more advanced level chemistry; students should be focused on looking past just the knowledge in the textbooks. Necessary prior knowledge includes basic knowledge of acids and bases; the pH scale, how to convert between pH and [H+] and physical/ chemical properties and changes. This unit is something that is done farther into the semester after students have covered general chemistry concepts.

Assumptions:

• I am not a floating teacher, and have a sufficient lab to complete procedures in

• Students have an understanding and have signed a lab safety contract; they also have already been assigned into a group of 3.

• There are sufficient materials for each group to have their own set of beakers; there is enough materials for each group to test the pH but they must divide everything up in an appropriate manner. To alleviate too much traffic around the classroom this model will be used: having one person in each group responsible for materials, having a trashcan in the middle of the room, having sufficient paper towels, and also alleviating useless traffic in the laboratory.

• Each period is a 70 minute period

• There is a computer lab open to use on the 3rd day of this unit

Calendar:

Day 1 (Introduction/lab): Cabbage pH scale protocol

Day 2 (Problem posing) :, Research and pose scientific problem for next class

Day 3 (Problem solving): Utilizing protocol after problem has been posed

Day 4 (Problem persuasion): Put together lab report

Day 5 (Problem persuasion): Students will be condensing their lab reports into a transparency in order to present to the rest of the class their findings.

Class: 11th grade Chemistry

Topic: Cabbage Chemistry Day 1

Objectives:

• Students will be able to investigate that properties of acidic and basic substances based on previous knowledge

• Students will be able to identify acidic and basic levels by comparing to known colors and characteristics.

Standards Addressed:

• Physical Science

o Structures and properties of matter

▪ Atoms interact with one another by transferring or sharing electrons that are furthest from the nucleus. These outer electrons govern the chemical properties of the element.

Materials:

• Red cabbage

• Blender

• Boiling water

• Filter paper (coffee filters work well)

• One large class beaker or other glass container

• Six 250 mL beakers or other small glass container

• Dilute ammonia (NH3)

• Baking soda (sodium bicarbonate Na2CO3)

• Lemon juice (citric acid C6H8O7)

• Vinegar (acetic acid, CH3COOH)

• Cream of tartar (potassium bitartrate, KHC4H4O6)

• Antacids (calcium carbonate, calcium hydroxide, magnesium hydroxide)

• Seltzer water (carbonic acid H2CO3)

The cost of these materials is minimal due to the fact that it is mostly household materials being used in a chemical nature. A large blender would run $25 from

and students can share the blender. As the teacher I will have plenty of cabbage puree prepared before students get to class. Also needed are 2 boxes of coffee filters ($4 each) and also maybe 7 or 8 heads of red cabbage ($5 each depending on season), and also each of these household items to test pH which will add up to about $40. Overall, this lab will run around $100, including all materials and equipment. The cost can be defrayed due to the fact that many of the items students are testing can be found around the house so the cost can come down to about $60 or so.

Process:

ANT (5 minutes):

-As students come into the classroom, they should pick up the handout of the Acid/Base KWL chart and head quietly into their seats. Written on the board are their directions for the beginning of class:

“Fill out the K (what you know) portion of the KWL chart.”

-Allow students 2 minutes to fill this chart out and once that time nears tell students to wrap up what they are writing. Draw a KWL chart on the board and begin with students by asking ‘what do we already know about acids and bases?’ If students are hesitant to answer ask someone to come up and write down 1 thing they have on their chart.

-Once students are finished with their input to the KWL chart, ask students ‘what do you want to know about acids/bases? (this is where they should fill out the W part of the KWL chart). Again ask students what they want to know about acids/bases.

*** (This might be an area where students begin to wonder why acids/bases and knowing about them are important. This is something that we will come back to tom so students should be sure to keep this worksheet in a safe place.)***

Introduction to today’s lab (5 minutes)

Question: What is the pH scale used for and where on the scale does acidic, basic and neutral fall under? What is the pH of a solution with an [H+] concentration of 2.077x10^-12? Is this acidic or basic?

Answer: The pH scale is used to identify a substance’s level of acidicity or basicity; acid is less than 7, 7 is neutral, and greater than 7 is considered basic. The pH of this is 11.68 and is considered basic.

Red cabbage contains a pigment molecule called flavin. This water-soluble pigment is also found in apple skin, plums, poppies, cornflowers, and grapes. Very acidic solutions will turn it a red color while neutral solutions result in a purplish color. Basic solutions will appear in greenish-yellow. With this knowledge it is possible to determine the pH of a solution based on the color it turns the pigments in red cabbage juice.

Procedure** (45 minutes):

How acidic, basic, or neutral is a substance based on his pH level?

Students will be given this procedure on a stapled packet and will be given all but 10 minutes at the end of the period to complete

• Students will be using acids and bases so they should be wearing goggles and follow all protocols meaning hair pulled back and no open toed shoes among other things.

• Chop the cabbage into small pieces until you have about 2 cups of chopped cabbage. Place the cabbage in a large beaker or other glass container and add boiling distilled water to cover the cabbage. Allow at least ten minutes for the color to leach out of the cabbage. (Alternatively, you can place about 2 cups of cabbage in a blender, cover it with boiling distilled water, and blend it.)

• Filter out the plant material to obtain a red-purple-bluish colored liquid. This liquid is at about pH 7. (The exact color you get depends on the pH of the distilled water.)

• Pour about 50 - 100 mL of your red cabbage indicator into each 250 mL beaker.

• Add various household solutions to your indicator until a color change is obtained. Use separate containers for each household solution - you don't want to mix chemicals that don't go well together!

• Students should include a control of distilled water which should be at pH of 7

This is the comparative scale students are given to compare their substances to:

| pH  | 2  | 4  | 6  |

|Control | | | |

|Ammonia | | | |

|Baking soda | | | |

|Lemon juice | | | |

|Vinegar | | | |

|Cream of tartar | | | |

|Antacids | | | |

|Seltzer water | | | |

Students should also design a bar graph to correspond with the pH level they have indicated for each substance like so:

[pic]

Closure (15 minutes):

**it should be noted that the chemicals used for this are safe to be washed down the drain.

• Students should be nearing the end of cleaning up. Be sure that materials have been disposed of properly.

Homework:

For homework, they should complete calculations for possible [H+] concentration in the far right column of their chart. Also they should fill out the bar graph for the pH levels.

(pH = -log [H+] so therefore [H+]= 10^-pH).

(**lab protocol is taken from “How to Make Red Cabbage pH Indicator” at )

Class: 11th grade Chemistry

Topic: Cabbage Chemistry Day 2

Objectives:

• Students will be able to investigate that properties of acidic and basic substances based on previous knowledge

• Students will be able to communicate the importance of pH in our everyday life

Standards Addressed:

• Science as Inquiry

o Understandings about scientific inquiry

▪ Scientists conduct investigations for a wide variety of reasons. For example, they may wish to discover new aspects of the natural world, explain recently observed phenomena, or test the conclusions of prior investigations or the predictions of current theories.

• Physical Science

o Structures and properties of matter

▪ Atoms interact with one another by transferring or sharing electrons that are furthest from the nucleus. These outer electrons govern the chemical properties of the element.

Materials:

• KWL chart from previous day

• Computer lab for students to research

Process:

ANT (10minutes)

Have students get into their lab groups and have them go over their results. Everyone in the group should have the final column of the chart filled out. Have each group make a final chart and graph. Each member of the group should have a copy but also a copy for the group is essential.

Introduction to today’s activities (15 minutes)

Since our lab dealt with acid/base levels, begin a short discussion where we see acids and bases in our everyday life. What did our lab from yesterday tell us?

Peel an orange for students and take a bite into it. To students, exclaim how acidic this orange is. What does that mean? What about acid rain? Bring up the idea of how statues over time begin to not look the same. For example, show a picture of a statue from 100 years ago and present. What can you tell me about basic properties? What about milk-what can you tell me about it? Mylanta-when do you take that? What do you think it is doing? Where might this lie on the pH scale?

With what you know about acidic and basic properties, what can you do with this protocol we have?

Today you will be designing your own experiment using the protocol from the previous day. Students will be given criteria to include in their proposal and we will spend 30 minutes in the library for students to research and type up a short proposal.

Library (30 minutes) :

Students will work in their lab groups to design an experiment using the protocol from the day before. Remind students that the materials they will be testing need to be provided by themselves.

Possible questions for students to ask:

• What is the acidity/ basicity of household cleaners?

• Where on the pH scale do breakfast juices such as apple, orange or cranberry lie?

• What is the difference between the basicity/acidity or stream or lake water that lies in the shade and out in the sun?

• What is the acidity/ basicity of different types of water (i.e. tap, distilled, spring, seltzer, etc.)?

• What is the acidity/basicity of your everyday shampoo and conditioners (i.e. Pantene, Herbal Essences, Garnier Fructisse, etc.)?

Criteria for their proposal:

• What is your hypothesis?

• Materials?

• What is the background information of the items you will be testing?

• Why is this significant?

• What are your methods? How many replications?

• What are the conditions of your testing area? Dark or light? Temperature?

Back to the Classroom (15 minutes):

Students should have printed up their proposals at the library and bring them back to the classroom. Each group will present to the class what they are planning on doing for their protocol tomorrow in lab. Students should be sure to include the criteria for the proposal in their short presentation.

Homework:

Bring materials to test tomorrow for lab!!!!!

Continue with KWL Chart and include anything they have learned about pH/acids and bases

Class: 11th grade Chemistry

Topic: Cabbage Chemistry Day 3

Objectives:

• Students will be able to identify acidic and basic levels by comparing to known colors and characteristics

• Students will be able to follow through an inquiry based procedure based on a problem they have posed and communicate the results to the rest of the class

Standards Addressed:

• Science as Inquiry

o Understandings about scientific inquiry

▪ Scientists conduct investigations for a wide variety of reasons. For example, they may wish to discover new aspects of the natural world, explain recently observed phenomena, or test the conclusions of prior investigations or the predictions of current theories.

• Physical Science

o Structures and properties of matter

▪ Atoms interact with one another by transferring or sharing electrons that are furthest from the nucleus. These outer electrons govern the chemical properties of the element.

Materials:

• Red cabbage

• Blender

• Boiling water

• Filter paper (coffee filters work well)

• One large class beaker or other glass container

• Six 250 mL beakers or other small glass container

• Materials that students have posed their problem to test on

Process:

ANT (10 minutes):

Have them turn in their protocols done the day before. Students should also have a copy for themselves now as well. Students will be given the first 10 minutes of class to get their materials together and to read over the protocol again.

Procedure (45 minutes):

The same procedure will be followed except that students will be applying it to the question they have posed. It goes as follows:

• Students will be using acids and bases so they should be wearing goggles and follow all protocols meaning hair pulled back and no open toed shoes among other things.

• Chop the cabbage into small pieces until you have about 2 cups of chopped cabbage. Place the cabbage in a large beaker or other glass container and add boiling water to cover the cabbage. Allow at least ten minutes for the color to leach out of the cabbage. (Alternatively, you can place about 2 cups of cabbage in a blender, cover it with boiling water, and blend it.)

• Filter out the plant material to obtain a red-purple-bluish colored liquid. This liquid is at about pH 7. (The exact color you get depends on the pH of the water.)

• Pour about 50 - 100 mL of your red cabbage indicator into each 250 mL beaker.

• Students will use their experimental substances to add to the indicator until a color change is obtained. Use separate containers for each substance - you don't want to mix chemicals that don't go well together!

• Students should include a control of distilled water which should be at pH of 7

This is the comparative scale students are given to compare their substances to:

| pH  | 2  | 4  | 6  |

|Control | | | |

| | | | |

| | | | |

| | | | |

| | | | |

| | | | |

| | | | |

Students will also create a table similar to yesterdays to be used in a lab report later:

[pic]

A,B,C etc is indicative of what students will test

Closure (15 minutes):

Students should clean up their lab stations in a timely and efficient manner. Also students’ substances should be safe to wash down the drain seeing as how most of them probably came from around the house. Students should hopefully finish cleaning up and putting away materials within 10 minutes and with the remaining 10 minutes students should head back to the classroom. Pose students the question of ‘did they come into class with already having made their mind up about where their substances would land on the pH scale and what led them to believe that;” also “how did their substances end up doing with the pH indicators?’ Students will be spending the next day in the computer labs writing up their lab report according to a layout they will be given. Students should also be thinking about the significance of their results-what does this mean to our everyday knowledge about the substances?

Homework:

Nothing is due for tomorrow but students should come in prepared to start and complete their lab reports in the computer lab tomorrow.

Class: 11th grade Chemistry

Topic: Cabbage Chemistry Day 4

Objectives:

• Students will be able to design and follow through an inquiry based procedure and communicate the results to the rest of the class

Materials:

• Data from lab completed the previous day

• Packet with procedure, etc given on first day of lab

• Computers in the lab

• Graph paper

Standards Addressed:

• Science as Inquiry

o Understandings about scientific inquiry

▪ Scientists conduct investigations for a wide variety of reasons. For example, they may wish to discover new aspects of the natural world, explain recently observed phenomena, or test the conclusions of prior investigations or the predictions of current theories.

Process:

ANT (10 minutes):

The ANT for today will consist of students getting together quietly into their lab groups and discussing their results and reviewing the outline give for writing a lab report (see following page). They should just sketch what each part will entail so they have an idea of what they will be doing once they get into the computer lab. Once they have had ample time to work on this, students should head into the computer lab in a quiet manner. Remind students that a lab report is straight to the point and simple; they need not include any unnecessary details due to the fact that they are only allotted 50 minutes or so to complete it in the computer lab.

Procedure (45 minutes):

• Once in the computer lab, students, in their groups, should be at a computer working on the lab report. Students should designate someone to type what is being dictated for the lab report. This student should be someone who is competent with typing and computers. Students have the outline of a lab report and it should be followed exactly for what they are working on.

• If students do not feel comfortable making tables or graphs on the computer they are also allowed to free hand them on graph paper (provided to them by the teacher). They should have a table similar the one they completed in lab and a graph similar to the one they completed in lab.

• You should be walking around monitoring students progress and once students are working on the conclusion, remind students to go back to the original question they posed as a guide for writing their conclusion.

• Remind students also, even though it is in the outline, that they should also include any errors that may have occurred and how they could fix them. Also other things they could have tested within the topic of their question.

• At 10 minutes, students should have completed the first 3 bullets of the outline; after 20 minutes students should have completed the next 3 bullets and the last 20 minutes should be spent on finishing the results and working on the conclusion.

Closure (15 minutes):

• Students should be nearing the end after being allotted 45 minutes to work on their lab reports and when finished should print out their lab report to turn in.

• Lead a short discussion with students on how they felt about writing the lab report (i.e. did they feel the outline was sufficient, was there enough time to complete it)

• Allow students to read over their lab reports one last time to make any last minute corrections and then have them turn them in.

Homework:

NONE!!!

Class: 11th grade Chemistry

Topic: Cabbage Chemistry Day 5

Objectives:

• Students will be able to design and follow through an inquiry based procedure and communicate the results to the rest of the class

Materials:

• Copy of lab report from previous day

• Transparencies

• Overhead markers

Standards Addressed:

• Science as Inquiry

o Understandings about scientific inquiry

▪ Scientists conduct investigations for a wide variety of reasons. For example, they may wish to discover new aspects of the natural world, explain recently observed phenomena, or test the conclusions of prior investigations or the predictions of current theories.

Process

ANT (15 minutes):

Directions for today:

Today you will be presenting your results to the rest of the classroom. You will be given about 15-20 minutes to condense your lab report and findings to this single transparency. When condensing your lab report, remember those criteria you used when writing your proposal and also with your results/discussion be sure to include the important points. You have 20 minutes to put together your lab report on this transparency.

Process (40 minutes)

Allow each group about 4-5 minutes to present their lab report transparencies. When students are presenting what they are testing make sure they tell the class why this is significant. Also ask students why they chose to test this. Students will be given a small participation grade for this presentation based on including a short bit about each section of the lab report and particularly why their proposal is significant.

Closure (15 minutes)

Have students judge each groups lab report/presentation on the following 3 criteria: significance, ability to follow the original protocol, and completeness. It is important for students to write if the agree of disagree with the significance of the other groups’ lab protocols. To do this students will pass the lab reports around (each group should bring in a copy with no names on it for this part). Students have the lab reports to refer back to after viewing the presentations. Each group will only have to evaluate 4 groups. They will do this on a separate sheet of notebook paper with no names on it. Have them pass these up along with the nameless lab reports.

Homework:

Have students complete their KWL charts to turn in tomorrow

LAB REPORT OUTLINE

I. Title (i.e. testing acidity/basicity with cabbage on …….)

II. Authors

III. Introduction

A. the question posed

B. the significance of the research question

IV. Procedure

A. for 2nd day in the lab

V. Results

A. include table and graph (be sure to label axes)

VI. Conclusion

A. What was the answer to the research question?

B. What were some errors that you might have run into? How might you correct that if you were to do this again?

C. Is there anything else you could have tested or a variable you might have changed if you were to do this again?

*outline taken from syllabus for Teaching Science in Secondary School (KSU) with Dr. Matthew Weinstein Fall 2005.

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