pH, Carbon Cycle and Ocean Acidification
Grade Level: Middle and High School
Concepts: pH scale; buffering capacity; basic chemistry review; biogeochemical cycles (carbon
cycle); interdependency of atmosphere, hydrosphere, lithosphere and biosphere; earth
systems; ocean acidification; science process skills; controlled experimentation
GPS: SCSh1; SCSh3; SCSh6; SC7; SES6; SEC4; SEC5
Ocean Literacy Principles:
#2 The ocean and life in the ocean shape the features of Earth;
#3 The ocean is a major influence on weather and climate.
#6 The ocean and humans are inextricably interconnected.
Duration: Each part may be used independently or done as demonstrations.
Lesson & Lab #1: pH Intro - 30 min.
Lesson & Lab #2 : pH Lab and Reflection - 50 min.
Lesson & Lab #3: Connection to the carbon cycle and Ocean Acidification - 55 min.
Focus questions:
What does the pH scale measure?
How do carbon dioxide levels in the atmosphere affect the pH of river/pond water and
ocean/seawater?
What is a biogeochemical cycle?
What are the sources and sinks for carbon?
How could excess carbon dioxide in the atmosphere and the oceans cause ocean
acidification?
What are some ideas for experiments to test the affect of ocean acidification on marine
life?
Objectives: Students will:
Describe the how the pH scale is used to determine acid versus basic or alkaline
solutions.
Relate how carbon dioxide levels affect pH levels of distilled water, river/pond water
and ocean water (seawater).
Describe the carbon cycle to include sources and sinks.
Infer how excess carbon dioxide levels in the atmosphere is leading to ocean
acidification
Suggest ways to test for ocean acidification’s impact on marine life
Background Materials for teachers: Prerequisite knowledge
Preview PowerPoint for lesson Carbon Dioxide and Ocean Acidification provided or
make one more suitable for you subject area and grade level.
Read Fact Sheet: Ocean acidification- PMEL Fact sheet
http://pmel.noaa.gov/co2/files/noaa_oa_factsheet.pdf
More teacher review resources are listed below:
pH- measure the concentration of hydrogen ions;
http://staff.jccc.net/pdecell/chemistry/phscale.html; acids and bases review http://lrs.ed.uiuc.edu/students/erlinger/water/background/ph.html
Vocabulary:
alkaline
acidic
buffer
dissociation
salt
solution
control
chemical equation
reactants
diffusion
variable
constants
sources
sinks
carbon cycle
products
Summary of Lessons & Labs:
Lesson & Lab #1: pH Intro – 30 min.
1. Distribute student KWL Inquiry Sheets for lesson and have them fill in the ‘K’ or first
column of the KWL chart with what they think they already know for question #1.
2. Show slides 1-6 of PowerPoint presentation
3. Have students fill in the ‘L’ column of KWL Inquiry Sheet with what they learned for
question #1.
Lesson & Lab #2: pH Lab and Reflection- 50 min.
PLEASE NOTE: This Lab can be done as a demonstration. Also, the Lab Report can serve as a
report format to accompany the Student Worksheet or as a stand alone open lab guide.
1. Have students fill in the ‘K’ column for questions #2-3.
2. Have students conduct the lab or after you have performed the demonstration with the
students. Have students fill in their data on the Student Worksheet and/or Lab Report.
3. Have students summarize findings in the ‘L’ column for questions #2-3.
4. Have students answer questions the Student Worksheet.
Lesson & Lab #3: Connection to the carbon cycle and Ocean Acidification - 55 min.
1. Distribute the KWL Inquiry Sheet and have students complete the “K” column on KWL
for questions #4-7
2. Show PowerPoint slides (7-13) about the carbon cycle and ocean acidification. Students
complete “L” column of KWL Inquiry Sheet questions #4-7
3. Have students complete Student Worksheet questions and summary activity.
Extension- Students propose experiments to investigate the impact of ocean acidification on
marine life.
Assessment: KWL Inquiry Sheet and reflection questions on the student worksheet
Extensions: Students do a webquest to discover what types of experiments are already being
conducted on ocean acidification. Students participate in the virtual labs pertaining to ocean
acidification like Virtual Urchin: http://virtualurchin.stanford.edu/AcidOcean/AcidOcean.htm
or the Assessing Water Quality Virtual Labhttp://www.mhhe.com/biosci/genbio/virtual_labs/BL_09/BL_09.html
Additional resources:
Acids and Bases – Brain Pop
http://highered.mcgraw-hill.com/sites/dl/free/0078617650/164037/00053406.html
tutorial-Acids and bases /conductivity
http://www.elmhurst.edu/~chm/vchembook/185strength.html
European Project on Ocean Acidification website- posters; animations; overviews; additional
experiments including the role of bicarbonate and carbonate ions in buffering seawater
http://www.epoca-project.eu/index.php/what-do-we-do/education/classroom.html
NOAA PMEL Carbon Programhttp://pmel.noaa.gov/co2/story/Ocean+Acidification
WHOI http://www.whoi.edu/OCB-OA/page.do?pid=40276
podcast and videos- http://www.whoi.edu/OCB-OA/page.do?pid=32865
numerous links to resources- http://www.whoi.edu/OCB-OA/page.do?pid=32866
NOVA Science In the Newshttp://www.science.org.au/nova/106/106key.htm
Ocean Carbon and Biochemistry Program
http://www.us-ocb.org/publications/OCB-OA_labkit102609.pdf
Center for Microbial Oceanography
http://cmore.soest.hawaii.edu/education/teachers/science_kits/ocean_acid_kit.htm
Credit to Vicki Soutar, Oconee County High School in Oconee County, Georgia, in collaboration
with Brian Hopkinson (UGA Marine Sciences Department) with funding from the National
Science Foundation (Award #1041034) and assistance from the Center of Ocean Sciences
Excellence Education SouthEast (COSEE SE).
More lessons available at www.cosee-se.org