Teams in Engineering ServiceMiddle School Environmental

Education Team Winter 2010

Zachary AlsagoffJeff Chang

Shih-Paul ChenRaj KhatriBrent Lee

Zachary LermanDivine Mon

Kristen NguyenJoshua RamosAlex Tiscareno

Alan ToledoMax Twogood

TA: Julianna WangAdvisor: Jan Kleissl

TABLE OF CONTENTS

1. Introduction ZACH L, PAUL..................................................................32. Quarter Goals ZACH L, PAUL...............................................................33. Handheld PM Sensor ZAC A, ALEX, JOSH.........................................4

Quarterly Update.....................................................................................................................................4Background.............................................................................................................................................4ADC Program.........................................................................................................................................4Assembly.................................................................................................................................................5Vernier Sensor Attachment.....................................................................................................................6

4. Outdoor PM Sensor JEFF …………………………………………. …8

5. Lesson Plan Development.........................................................................9Front Row Fiasco ALAN........................................................................................................................9Blown Away MAX...............................................................................................................................10Shell Shocked BRENT.........................................................................................................................10

6. Classroom Visits RAJ, DIVINE.............................................................11Introduction...........................................................................................................................................11Coordinating Visits...............................................................................................................................11Contacts.................................................................................................................................................12I-Test Teacher Visits.............................................................................................................................13Outreach Beyond Teacher Visits..........................................................................................................13

7. Budget KRISTEN....................................................................................148. Appendix..................................................................................................14

ADC Source Code............................................................................................................15

1. INTRODUCTION

The main objective of the Teams in Engineering Service (TIES) Middle School Environmental Education (MSEE) team is to inspire middle school students to find careers in science and engineering. Studies have shown that this is the age group where interest in science and engineering in students take the most dramatic downturn, especially in females. In today’s world, being environmentally aware has taken on a new role in society, so by establishing the foundation of environmental awareness, students may engineer new methods to preserve the ecosystem in the future. To accomplish these goals, the MSEE team focused on a variety of different objectives. The first was to develop new environmentally based lesson plans for middles school students. This quarter, the team created lesson plans which deal with ocean acidification, corrosion of ocean life, and the reason why chalk is not used in classrooms. Next, each team member visited middle school classrooms participating in the I-TEST program and assisted the teachers in performing the experiments that have been developed in the past. Lastly, the MSEE team focused on the repair and improvement of a recently fabricated device designed to sense particulate matter.

2. QUARTER GOALS

Develop new lesson plans and present them to host teachers

At least two Classroom visits per team member

Improvement and repair of additional handheld PM sensors

Re-coding the outdoor PM sensor and making it operational

Participation in the Science Olympiad

Participation in the San Diego Science Alliance

3. HANDHELD PARTICULATE MATTER (PM) SENSOR

Quarterly Update

One of the challenges this quarter was coming up with a solution to add an enclosure for the handheld PM sensor’s battery. This was solved by affixing the bottom covers with screws to ensure the 9V batteries were held securely within the casing.

Looking into the sensors, it was found that they were unable power on. After labeling the three current handheld PM sensors as I, II, and III, new battery replacements fixed the problems for labeled sensors I and III. The batteries are prone to drain, so in the meantime, the sensors were plugged into an AC outlet in the wall. This is not a permanent solution as the sensors will ideally be used away from outlets for some experiments.

Further analysis of sensor II determined that it had a faulty LCD display. This most probable cause was because of the poor soldering job, which overheated the circuit on the LCD. The solution to this was ordering a new screen from PARALLAX and installing it. After installation, it appears to be functioning with the exception of its outputted readings. The solution can be found by uploading the code for the handheld PM sensors located in the appendix.

Background

Air quality is becoming more of an environmental concern due to the advancement and utilization of products and procedures. Many of these products emit pollutants that are deemed unhealthy, if not hazardous, to one’s personal health. Automobiles, for instance, emit carbon monoxide that is a colorless and tasteless yet highly toxic gas. Combustion pollutants from burning fossil fuels can contribute to birth defects. Cigarette smoking as well as passive smoking provokes higher risks of asthma. Even common beauty supplies such as hairsprays contain many chemicals that result with various forms of irritation and nausea. Introducing students to air quality education at a younger age can teach awareness of these pollutants and, perhaps, inspire them to pursue and generate newer, environmentally -friendly products and procedures.

This TIES team is focused on developing a particulate matter (PM) sensor to accompany lesson plans on air quality. The main goal is to produce a light and portable system that allows students to manipulate and retrieve live data of the ambient air quality. This sensor is able to detect solid particles, such as dust and pollen, within a 1 to 10couple micrometers in size. This quarter the work on the sensors was mainly centered on improving the enclosures, especially the bottom where the battery was held, along with testing for functionality. Unexpectedly, one of the sensors LCD screens died, so it was replaced with a new one, as well as re-soldering the wires.

ADC Program

Some slight changes were made to the components on the newly built sensor. In particular, a much smaller ADC was used. Since we purchased a smaller ADC, we needed to alter the stamp controller program to display the measurements. , whether displaying eEach individual measurement can be displayed or displaying an average of the measurements taken within a time frame can be shown. The pin outs from the stamp controller side are as follows:

Use of PM Sensor:1. The sensor must be vertical i.e. the screen should be pointed towards the ceiling.2. The screen should never read 0. If it does, the wire from the sensor to the ADC chip is

loose and needs be reattached, even if it looks fine.3. Air flows from the bottom to the top so whatever source is being measured should be on

the bottom.4. The output of the sensor will not stabilize. Results it gives have been tested against a high

grade PM counter. The output of the handheld sensor ranges around an accurate count.5. Make sure to use provided charger to recharge batteries.

Assembly

This quarter, we used a different Analog to Digital converter (ADC) than in previous quarters. The previous design called for a 20-bit ADC, which was more than enough, so we went with an 8-bit ADC as a simpler model. We connected all the pins to the stamp controller by connecting VDD to pins 8 and 5 and grounding pins 1, 3, and 4. We connected the remaining pins to pins connected to the stamp controller as they are used for the data in and out of the clock.

For the LCD Backlight Screen, we soldered wires to the RX, 5V and GND parts of the backside of the screen. This allowed us to connect the wires to the stamp controller so that it could receive an input and output to display desired results.

We needed to find connectors for the particulate matter sensor because we were missing some sets. We purchased a set of 4

pin and 3 pin connectors as shown and are figuring out ways to incorporate longer strands of wires to connect it to the stamp controller.

We assembled two more enclosures to hold the particulate matter sensors. We used 3/16-inch clear acrylic to assemble front panels and covers. Each component was glued together using acrylic cement/glue. The hardware was screwed in using 4-40 machine bolts and the complementing nuts and washers. The cover and battery plate are screwed to the front panel using 4-40 machine bolts. Each hole was tapped for these bolts; not tapping the holes can possibly result with cracked acrylic.

Vernier Sensor Attachment

An idea we investigated this quarter was possibly adapting the handheld particulate matter sensors to use the Vernier LabQuest handheld unit. While the idea was feasible, the LabQuest software would have to be customized whenever using the sensor. The analog voltage from the sensor could be displayed on the screen for the Vernier LabQuest unit, but special parameters would have to be set on the unit to convert the voltage into a particulate matter count. This would be an added level of complexity when using the LabQuest unit. This would have little value considering that the group already has standalone sensor units.

4. OUTDOOR PARTICULATE MATTER (PM) SENSOR

Quarterly Update

The team has been developing a weather-proof particulate matter sensor suitable for outdoor use. The sensor measures temperature, humidity and particulate matter density in the air and broadcasts the data over Bluetooth. Throughout past quarters, the team has attempted to integrate a USB data logger into the sensor. The data logger would record and store the data in a USB flash drive. However, due to the limited input/output capability of the microcontroller, it was very challenging to incorporate a reliable data logger that doesn’t require frequent resets of the microcontroller.

Solution

A companion computer program to fetch, timestamp and store the data was proposed as an alternative solution to complement the outdoor sensor. The computer program can be run on a computer with Bluetooth capability. The data can be displayed on screen in real time or stored as a comma-separated-value (CSV) file to be ported into spreadsheet software later for future analysis. A command-line interface provides user options on where to store the file, how many measurements to take, and whether to append to an existing file or to replace it.

Use Cases

A typical scenario of the outdoor sensor consists of relocating installing the sensor to at a local participating middle school in San Diego and , collecting continuous data, and moving the sensor to a new location. The period over which data is collected may range from a few minutes to a few hours. Identical sensors installed at other schools will allow The main objective of the sensor is to comparinge air quality amongst schools, rather than over long periods of time and during specific events such as forest fires..

Development Requirements

The requirements features of the program are listed below in priority from high to low:(1) Ability to receive data from sensors over Bluetooth(2) Timestamp the measurements(3) Store the data collected(4) User interface to display data collected

Sample Output

A sample output file from the program as well as a graph created from the data is provided below.

Date TimeParticles

per Liter

Temperature (deg C) Humidity

3/2/2010 16:33:55 137 20 21 543/2/2010 16:33:56 135 25 21 543/2/2010 16:33:58 121 14 21 54

3/2/2010 16:34:00 134 21 21 543/2/2010 16:34:02 128 25 21 543/2/2010 16:34:11 157 15 21 543/2/2010 16:34:12 140 19 21 543/2/2010 16:34:14 110 20 21 543/2/2010 16:34:16 130 52 21 543/2/2010 16:34:18 207 34 21 553/2/2010 16:34:20 194 45 21 573/2/2010 16:34:22 225 42 21 603/2/2010 16:34:24 183 24 21 643/2/2010 16:34:26 158 26 21 663/2/2010 16:34:28 244 45 21 683/2/2010 16:34:30 264 55 21 703/2/2010 16:34:32 270 50 21 713/2/2010 16:34:34 281 40 21 723/2/2010 16:34:36 297 32 21 73

Known Issues

Due to time constraints, many issues were not addressed in the development of the companion program. The program was written in C, one of the most portable programming languages available. In theory, the program should work flawlessly in other UNIX-like operating systems. However, the program relies on low-level serial communication with the sensor’s Bluetooth transmitter and was never tested on operating systems other than Mac OS X, the platform on which it was developed. The program may also require some reconfiguration, available in the user interface, mainly because of the differences of how device files are implemented by various operating systems.

5. LESSON PLAN DEVELOPMENT

This quarter the team was divided into three sub-groups; each sub-group would work on a separate project. One team worked on the outdoor PM sensor, a second team worked on the handheld PM sensor, and the third team worked on developing new lesson plans for the middle school students. Please note that all three lesson plans that have been developed this quarter can be found in the appendix.

“Front Row Fiasco”

One of the goals this quarter in terms of developing lesson plans was to incorporate the handheld particulate matter sensor. The team developed the handheld PM sensor to help students understand particulate matter and its effects on the environment, yet we have no set method of demonstrating this to the classroom. The lesson plan “Front Row Fiasco” achieves this by incorporating particulate matter that students deal with on a daily basis, chalk dust.

The lesson plan is designed to see how the concentration of particulate matter changes with increasing distance as well as time. The materials for the lesson plan include, chalk, anti-dust chalk, erasers, the particulate matter sensors, a stop watch, and a meter stick. One particulate matter sensor is placed at the “front row” of the class room while another is placed in the back. Chalk dust is then created at the front of the classroom by clapping the chalk dust erasers pre-loaded with chalk dust. The concentration of particulate matter is to then be recorded for both sensors at different time intervals. Students can then conclude how factors in the environment such as the distance from a construction site or forest fire, as well as wind affects the concentration of particulate matter. The complete lesson plan is provided in section 7.2. in the appendix.

“Blown Away”

“Blown Away” is the first experiment in a two-part lesson plan. The purpose of the lab is to show how atmospheric carbon can dissolve in Earth’s bodies of water and increase their acidity, ultimately affecting the organisms that live there. “Blown Away” is specifically designed to show that atmospheric carbon dioxide can decrease the pH of ocean water. To demonstrate this we incorporated the use of the Vernier LabQuests, which hold the ability to plotcan sense and graph a multitude of property changes over timevariety of parameters, including pH.

This experiment consists of three trials: a control using room temperature tap water, one experimental using room temperature “seawater,” and one experimental using cold “seawater.” The “seawater” is made using ordinary fish tank sea salt and tap water in order to simulate actual seawater with a pH of about 8.1.The students will obtain their solutions from the teacher in beakers and return to their desks with a partner. One student will blow bubbles through a straw into one of the solutions, while the other student will hold the pH probe connected to the Vernier

LabQuest in the solution. The LabQuest will plot a live pH versus time graph. After, and once the two minutes are done the students will be able to record their data and repeat the process for the next two trials. The cold trial is simulated by doing the trial in an ice bath. Ideally one student should always do the breathing to get accurate results, but its fine to let them switch roles if they want to.

This experiment is catered more towards 7th and 8th graders because it introduces basic concepts behind chemistry, such as what a chemical reaction is and what reagents and products are. Prelab questions and key terms are presented at the beginning of the lab to reinforce the concepts that are brought up in the lab introduction and outline appropriate teacher-student pre-lab discussion. Students will be able to hypothesize what they expect to see, and upon completion of the experiment they will have post lab questions to help them understand what they learned, how this is related to the actual environment, and they will brainstorm preventative measures that can be taken to reduce ocean acidification.

“Shell Shocked”“Shell Shocked” is the second part to the two-part

lesson plan. The purpose of the experiment is to demonstrate the effects of ocean acidification on the shelled organisms in oceans. Concepts from the “Blown Away” experiment will be put to use and the students will use their gained knowledge into predicting the effects of vinegar (a proxy for more acidic ocean water) on mussels. Students will be asked pre-laboratory questions, prompting them to think about what shells are made of and how an increase in carbon in the atmosphere will affect ocean pH. Over the course of this experiment, the students will realize the effects of increased carbon in the oceans (ocean acidification) on sea life.

The students will be provided with a bag of pre-treated mussel shells and a bag of untreated mussel shells. In this experiment, vinegar will act as the experimental factor and the seawater will act as the control. The students will place one untreated mussel half into vinegar and the other half into seawater and observe and record for a 30 minute period. The pre-treated shells included one low short exposure (4-6 hours) mussel shell and one longhigh exposure (16-18 hours) mussel shell. The students will be asked to compare the short and longlow exposure and high exposure mussels to the results they receive. The students will compare the differences in appearance, weight, translucency, and other physical factors. The lab also incorporates the use of the Vernier LabQuest and the pH probe. Students will measure the pH of the seawater and the vinegar while also using the timer within the Vernier LabQuest.

Upon finishing the experiment, the students will answer questions related to the lab and write a conclusion based on their hypothesis and what they learned. They will also come up with possible solutions for preventing or mitigating ocean acidification.

5. CLASSROOM VISITS

Introduction

Throughout the quarter, TIES students participate in the project “Information Technology-Engineering and Environmental Education Tools” (ITEST1). ITEST is lead by UCSD Jacob’s School of Engineering, in partnership with the San Diego Super Computer Center (SDSC). ITEST works with San Diego middle school teachers to develop hands-on environmental science experiments, utilizing the Vernier LabQuest handheld sensors.2 TIES students attend middle school classes during when these experiments are conducted by the teachers, and providinge technical and scientific support to the teachers while using the LabQuest sensors. The lesson plans and LabQuest sensors are designed to spark student interest in science and technology as well as increase student awareness about current environmental issues.

Coordinating Visits

A team member in TIES will be assigned as the teacher visit coordinator at the beginning of each quarter. The coordinator is responsible for arranging the visit schedule which best accommodates both teachers and TIES students. The following is a guideline on how the organization can be done efficiently:

1) Access ITEST coordination website to obtain equipment rotation schedule. The rotation schedule provides information on which teacher(s) will have the equipment during which week(s).

2) Contact teacher(s). Contact the teacher(s) a week in advance to inquire their class schedule (day and time). This is done primarily on email, and preferably on Monday to give the teachers time to respond.

3) Create a poll online. After obtaining teachers’ schedule, create an online poll (www.doodle.com). The rest of the team will provide their availability using the poll, and the coordinator can decide on the visit time that best accommodate both the teacher(s) and the TIES students. The poll is generally created on Wednesday.

4) Inform the teacher(s) of the visit times. After obtaining the result from the poll, the coordinator will contact the teacher(s) with the visiting times for the following week. This is also done via email, preferably early Thursday so the teacher(s) will have time to respond before the weekend. Ask the teacher(s) to respond in email as a confirmation on the schedule.

5) Confirm with teammates. Upon receiving the confirmation from the teacher(s), inform teammates with date, time, and location of the visit.

6) Fill out a participation survey. After each visit, participated TIES students are required to fill out an online survey form for the ITEST research team to gather data about the lessons.3 Additionally, participants need to answer the following questions to complete the survey process:

a. Teacher Name:b. Observation Date:c. How prepared was the teacher to lead the lesson you observed? (Choose one)

1 http://ties.ucsd.edu/ITEST/aboutite3tools.html2 http://www.vernier.com/labquest/3 http://www.grgsurvey.net/cgi-bin/rws3.pl?FORM=LessonReportCard

i. Extremely prepared – he/she had seemed to have reviewed the lesson plan ahead of time, the lesson seemed to be implemented according to a clear plan, and the teacher experienced few (if any) hiccups

ii. Generally prepared – he/she seemed to have reviewed for the lesson and seemed to have a general plan, but the lesson would have benefited from more specific planning

iii. Unprepared – he/she had not reviewed the lesson beforehand and/or did not seem to have a clear plan for the lesson

iv. Why did you choose that rating? (No more than a few sentences)

Contacts

Questions regarding overall ITEST operationJulie Humphrey jchumphr@ucsd.edu

Equipment AllocationEzequiel Noyola enoyola@ucsd.edu

Teachers involved in the Middle School classroom visits for 2009-2010

Teacher Name School Name Contact InfoMichelle Thorsen Dehesa Charter School michellethorsen@sbcglobal.netPamela Goalwin Julian Charter School pgoalwin@juliancharterschool.orgWayne Strong Foothills Christian High School wayne.strong@foothillschristianschool.comRachel Poland Innovation Middle School rpoland@sandi.netBen Vosburgh Innovation Middle School bvosburgh@sandi.netMadeline Hardson DePortola Middle School mhardson@sandi.netSarah Flynn Christian Junior High School sflynn@christianunified.orgGeoff Birch Guajome Park Academy BirchGe@guajome.netMichael Mertz Muirlands Middle School mmertz@sandi.netLindsay Hellman Guajome Park Academy HellmanLi@guajome.netMarj Atkisson UCHS matkisson@sandi.netArlene Peck Guajome Park Academy peckar@guajome.netKamyar Pourhamidi Correia Middle School kpourhamidi@gmail.comCatherine Peavy I-High Online cpeavy@sandi.net

I-Test Teacher Visits This Quarter

This quarter we visited Ben Vosburgh’s class at Innovation middle school. The class was an elective class so the students were really interested in science and were pretty well behaved. Below is a log of all the teacher visits conducted by the team this quarter as well as who attended the Science Olympiads

Student Name Teacher Visits Science OlympiadsAlan Toledo 0 1Zachary Alsagoff 3 0Zach Lerman 2 2Divine Mon 2 1Jeff Chang 1 1Raj Khatri 3 2Kristen Nguyen 2 2Alex Tiscareno 1 2

Paul Chen 3 2Brent Lee 2 1Max Twogood 2 2

Outreach Beyond Teacher Visits

Besides doing teacher visits, the team tries to participate in various outreach activities throughout San Diego. This quarter our team participated in the San Diego Science Olympiad4 held Saturday, February 6th and 20th, and the San Diego Science Alliance5 held on March 10th.

This Science Olympiad competition requires teams from different schools to compete in various science events, ranging from creating a bridge to designing a battery run car. Arthur Zhang, a UCSD graduate student here at UCSD, volunteered to be an event captain at the competition. He asked for volunteers from MSEE to be assistant event captains, helping out during the day of the event. Our responsibilities included setting up for the competition as well as judging events and supervising the kids.

In the Science Alliance festival this year, our team set up a booth where we had team members demonstrating how ultraviolet rays from the sun affect your skin. Utilizing the Vernier LabQuest apparatus and the UV sensor, we showed students how sunscreen blocks a significant amount of UV rays, emphasizing its importance in prolonged outdoor activities. We also made the UV lab tie into engineering, by talking to students about the wave properties of UV rays, and how they are either reflected, transmitted, or absorbed.

6. BUDGET

This quarter our team had a $500 budget. The expenses for this quarter’s budget were allocated to three teams and lesson plans. Table XXBelow is shows the budget for this quarter and an itemizedation of the expenses:

Budget Report

Item Price

LED screen $24.99

9V batteries $7.46

Poster $13.99

Team bonding event $47.50

Total (Spent) $93.94

4 http://www.sandiegoso.org5 http://www.sdsao.org

7. Appendix

All drawings, models, and lesson plans from this quarter can be found on the MSEE page on the TIES website.

1i. ADC Source Code' {$STAMP BS2e} ' {$PBASIC 2.5} 'Program to convert analog sample to digital sample and output through LCD screen DIO CON 9 'Data in/out line on the stamp CLK CON 10 'Time communication between stamp and chipCS CON 11 'CS on ADC adc VAR WORD 'Data read from chip goes here conc VAR WORD 'actual concentration in part/Lcounter VAR BYTE avg VAR BYTE(20) TxPin CON 0 Baud19200 CON 32 HIGH TxPin

PAUSE 1000SEROUT TxPin, Baud19200, [22]PAUSE 500SEROUT TxPin, Baud19200, [12]PAUSE 500SEROUT TxPin, Baud19200, ["Turning on"]PAUSE 5000SEROUT TxPin, Baud19200, [12]PAUSE 500SEROUT TxPin, Baud19200, ["Sensor warm up", 13, "60 sec left"]

counter = 60DO WHILE (counter > 0)PAUSE 1000IF counter = 10 THENSEROUT TxPin, Baud19200, [149," "] ENDIFcounter = counter - 1SEROUT TxPin, Baud19200, [148, DEC counter] LOOP

SEROUT TxPin, Baud19200, [12]PAUSE 500SEROUT TxPin, Baud19200, ["Ready to take readings"]PAUSE 1000

main:counter = 0

'Take 5 readings from ADCDO WHILE counter <= 20'GOSUB Setup_ADChipLOW CLK 'reset clock HIGH CS LOW CS'SHIFTOUT 1, CLK,MSBPOST, [1111\4] 'pull CS low to initiate conversion SHIFTIN DIO, CLK, MSBPOST, [adc\9] 'read 8 bit number from ADCavg(counter) = adccounter = counter + 1LOOP

'Calculate average adcadc = 0counter = 0DO WHILE counter <= 20adc = avg(counter) + adccounter = counter + 1LOOPadc = adc / 20

'Clear ScreenSEROUT TxPin, Baud19200, [12]

'Calculate particles/LGOSUB Calculate_PperL

'Output concentration to screenIF adc <= 255 THENSEROUT TxPin, Baud19200, [DEC conc]SEROUT TxPin, Baud19200,[" particles/L"]DEBUG "Concentration: ", DEC conc, CRENDIFGOTO mainSetup_ADChip:

RETURN

'Input: adc'Output: concCalculate_PperL:IF adc <= 255 AND adc > 134 THENconc = adc * 232 - 16750ENDIFIF adc <= 134 AND adc >= 0 THENconc = adc * 107ENDIFRETURN

2. Front Row Fiasco Lesson Plan

Front Row Fiasco!Introduction:

Ever wondered about the clouds of white dust that fill the air whenever your teacher claps the chalk erasers together? It may seem funny at the moment, but think again! Is chalk dust harmful to breathe in? How much is the teacher breathing in? Is your health endangered just by sitting in the front row of the classroom?

Materials:1. 2 particulate matter sensors2. regular chalk3. anti-dust chalk4. chalk erasers and chalkboard5. tape measure or yard stick

Procedure:

1. Set up one particulate matter sensor three feet from the chalk board2. Place the other one at 5 feet from the chalk board3. Write something on the chalkboard and then erase it4. Clap the eraser to create chalk dust and record the difference in

particulate matter concentration with respect to distance5. See if the concentration changes after 10 seconds6. Repeat the procedure for 10, 15, 20 feet. Make sure that the same

amount of chalk dust is used by writing the same exact thing on the chalkboard for each trial

7. Repeat with anti-dust chalk and see if there is actually a difference

Results:Distanc

eRegular Chalk Anti-dust Chalk

Initial Concentration

Concentration after 10 seconds

Initial Concentratio

n

Concentration after 10 seconds

35101520

Discussion:1. How does the distance affect the concentration of chalk dust?

2. Does the concentration of chalk dust change over time? If so, what factors could cause this change?

3. What are some of the sources for error in the experiment (i.e. pressing harder on the chalkboard when writing, having something dusty near the particulate matter sensor, etc.)

4. Is there a noticeable difference between anti-dust chalk and regular chalk?

5. The prolonged exposure to particulate matter concentration is considered dangerous to breathe; based on your observations, is it really dangerous to your health to sit it in the front row of a classroom?

Blown AwayBrought to you by:

TIES: Middle School Environmental Education

Objective: Students will be able to collect pH and Temperature data using Vernier LabQuests. Students will plot pH data over time using Vernier LabQuests.Students will understand how carbon dioxide affects salt water.Students will propose potential solutions to decrease Carbon in the atmosphere.

Key Terms:

Exhale: Gas Exchange: Chemical Reaction: Dissolve: Acid: Base: Reagents: Products: Ions:

Introduction:

Have you ever blown bubbles in your drink before? Did you know that you are actually making it more acidic? When you exhale, you breathe out Carbon Dioxide. Blowing bubbles into a beaker of salt water will mix Carbon Dioxide with the water. This mimics the gas exchange that occurs between Earth’s atmosphere and oceans. You will track the resulting changes in ocean chemistry by monitoring changes in pH as you exhale into the salt water.

Remember: C=carbon, H=hydrogen, O=oxygen

Carbon dioxide (CO2), even as a gas, will dissolve in water (H2O). When Carbon Dioxide and water mix, these two reagents make a chemical reaction, where carbon, oxygen and hydrogen molecules bind to form an acidic product called, carbonic acid (H2CO3).

Chemical reaction: CO2 + H2O ó H2CO3

Pre- lab questions:1. What gas are you blowing into the water?

2. What happens to the gas when you blow it into the water?

3. How will blowing into the water affect its pH?

4. How does measuring the pH over time help understand the effects of you blowing into the water?

5. In this chemical reaction what are/is the reagent(s) and what are/is the product(s).

What do you expect the pH of seawater to be? How do you think temperature will affect the pH change in the seawater due to the reaction? How do you think the pH change in tap water will compare to the pH change in sea water (tap water pH ~7)? Hypothesis:____________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

Materials

Per Group: Shared Materials:Saltwater (Salt + tap water, ~100mL) Ice Bath500 mL beakers 2 straws1 Vernier LabQuest with pH and Temperature probes

Lab ProcedurePreparation

1. Assign a role to each group member

Seawater Trial1. Add 100 mL saltwater to a 500 ml beaker.

2. Connect pH probe to the Vernier Lab Quest

3. Recorder: Place the pH probe into the beaker containing your salt water and record its initial pH.

4. Breather: Begin exhaling through the straw. Be careful not to inhale through the straw.

Recorder: When Breather begins blowing, start the pH vs. time graph on the LabQuest

5. Breather: Exhale/blow at steady breathing rate for two full minutes.

6. Recorder: After two minutes, stop the graph and record your final pH.

7. Recorder: Sketch your plot in square A.

8. Rinse off the pH probe and dry it with a Kim Wipe.

Role in Group Student NameRecorderBreather

Room Temperature Tap Water Trial1. Add 100 mL tap water to a 500 ml beaker.

2. Recorder: Place the pH probe into the beaker containing your tap water and record its initial pH.

3. Breather: Begin exhaling through the straw. Be careful not to inhale through the straw.

Recorder: When Breather begins blowing, start the pH vs. time graph on the LabQuest

4. Breather: Exhale/blow at steady breathing rate for two full minutes.

5. Recorder: After two minutes, stop the graph and record your final pH.

6. Recorder: Sketch your plot in square B.

7. Rinse off the pH probe and dry it with a Kim Wipe.

Cold Tap Water Trial1. Add 100 mL tap water to a 500 ml beaker.

2. Place the beaker into an ice bath.

3. Connect Temperature probe to the Vernier Lab Quest. Measure and record the temperature of the water after 5 minutes of sitting in the ice bath.

4. Rinse off the Temperature probe and dry it with a Kim Wipe. Disconnect the Temperature probe from the Vernier LabQuest and set it aside.

5. Reconnect the pH probe to the Vernier LabQuest.

6. Recorder: Place the pH probe into the beaker containing your tap water and record its initial pH.

7. Breather: Begin exhaling through the straw. Be careful not to inhale through the straw.

Recorder: When Breather begins blowing, start the pH vs. time graph on the LabQuest

8. Breather: Exhale/blow at steady breathing rate for two full minutes.

9. Recorder: After two minutes, stop the graph and record your final pH.

10. Recorder: Sketch your plot in square C.

11. Rinse off the pH probe and dry it with a Kim Wipe.

Data:Known pH measurements: Seawater = pH ~8.0 Tap water = pH ~7.0

Data Table:

Seawater 0 second

s

30 seconds

1 min(60 sec)

1 min 30 sec (90 sec)

2 min(120 sec)

Temperature

pH ~25⁰ C

Tap Water (room Temp)

0 second

s

30 seconds

1 min(60 sec)

1 min 30 sec (90 sec)

2 min(120 sec)

Temperature

pH ~25⁰ C

Tap Water (Ice Bath)

0 second

s

30 seconds

1 min(60 sec)

1 min 30 sec (90 sec)

2 min(120 sec)

Temperature

pH

A)

Time - Seconds

pH

Seawater

B)

C)

Time - Seconds

pH

Tap Water (Room Temp)

Time - Seconds

pH

Tap Water (Ice Bath)

Analysis and Discussion of data:

1. As you blew through the straw, what were you adding to the water and how did that change the pH?

2. What did the LabQuest show us about the pH change of each solution over time?

3. Compare each trial. How did temperature affect the pH? Would a hot water trial show a higher pH or a lower pH than room temperature?

4. How did the pH change in tap water compare to the change in sea water at room temperature?

5. What does this tell us about the effects of carbonic acid in ocean water? How can tap water relate to other bodies of water in nature that are affected by carbon in the atmosphere?

Conclusion/Summary (Revisit your hypothesis.):

Shell Shocked!Brought to you by:

TIES: Middles School Environmental Education

Objective:     1) Students will be able to record and collect data and analyze results.    2) Students will propose possible solutions for the prevention of shell deterioration.    3) Students will be able to operate a Vernier Labquest unit and utilize pH and temperature sensors.   

Introduction:How is ocean life affected by increased carbon in the atmosphere? What is it about shells that makes them vulnerable to deterioration? Animals with calcium carbonate shells, like mollusks, clams, and mussels, are affected by the change in pH levels and temperature of the ocean. The life of our shells and ocean life is in your hands! Over the course of this experiment, you will realize the effects of increased carbon in the oceans (ocean acidification) on sea life.

Pre-lab Questions:    1) What are shells made of?

    2) What are some sources of the carbon dioxide in our atmosphere?

    3) How does an increase in carbon in the atmposhere affect ocean pH? Increase or decrease?

Main Question: How will a decrease in the pH of seawater affect shells in the ocean (i.e. clams and mussels)? What changes do you expect to see in the shell after being exposed to lower pH (i.e. vinegar or lemon juice)?

Hyphothesis:

Materials (Per Group):

1) Beakers (2, 500 mL recommended)2) Vinegar (~150 mL) 3) Seawater (Seasalt + Tapwater,

~150mL)4) Vernier Labquest + pH probe5) Mussels (Treated and Untreated)

6) Weight or mass scale7) Permanent Marker 8) Paper Towels9) Tweezers

10) Timer

Table AShell Control Experimental

Observations of Shell

Before Exposure

Weight Before

Observations

duringInitial

exposureObservations after

15 minutes

Observations of Shell After

ExposureWeight After

Table BShell Low Exposure High Exposure

Observations of

Characteristics

Table CSoluti

on“Seawater” Vinegar

pH

Lab Procedure 1) Remove both halves of your untreated shells from the zip lock bag.2) With a permanent marker label on the inside of one half “E,” for

Experimental, and on the other half’s inside “C,” for Control.3) In the table provided, write down your observations of the

characteristics of each shell half before the experiment.4) Weigh each shell-half and record the weights in table A.5) At the same time:

One person should place the shell-half labeled “E” into a beaker and pour just enough vinegar to completely submerge the shell.

The other person should place the shell-half labeled “C” into a beaker and pour just enough salt water to completely submerge the shell.

6) Use the Vernier LabQuest and pH sensor to measure the pH of the Sea Water. Be careful not to hit the shell with the sensor. Record your results in Table C.

7) Rinse off the probe and dry it with a kim wipe.8) Use the pH sensor again this time to measure the pH of the Vinegar.

Record your results in Table C. 9) Set timer on Vernier LabQuest for 30 minutes.10) In table A record what you see happening to the shells initially.11) While you wait record observations of shell characteristics for the

provided pre-treated shells labeled “L” for low exposure and “H” for high exposure in Table B.

12) In table A record what you see happening to the shells after 15 minutes

13) (Bubble Experiment)14) After 30 minutes remove the shells with tweezers from the

vinegar and salt water and place it on a paper towel to air-dry (do not wipe dry).

15) After they are done drying, weigh both the control shell-half and the experimental shell-half.

16) Record the final weights and observations in table A.

Discussion Questions (Post-lab Questions):

1) When you immersed the shells in vinegar, what happened? Was the vinegar acidic or basic?

2) What happened when you immersed the shell in sea water? Was seawater acidic or basic?

3) Compare your observations for your control shell, experimental shell, low and high exposure shells. Note the exposure time, appearance, weight, texture, and transparency.

2) How does observing the shells in vinegar relate to how sea life is affected by a lower pH of ocean water?

3) How are shelled organisms affected by the change in pH?

4) What is so important about the shells of these organisms in the ocean?

5) What can you do to help prevent ocean acidification and protect these animals?

Conclusion:

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