Mountain Stream Ecology Pre-site Activities

Mountain Stream Ecology - Pre-site Activities/Teacher Led

Grade Level: 5
Content Area: Life Science
Time to Complete: 45 minutes
Title of Program: pH preview

South Carolina State Standards Addressed:

5-1.1	Identify questions suitable for generating a hypothesis.
5-1.4	Use appropriate tools and instruments safely and accurately when conducting a controlled scientific investigation.
5-1.6	Evaluate results of an investigation to formulate a valid conclusion based on evidence and communicate the findings of the evaluation in oral or written form
5-1.8	Use appropriate safety procedures when conducting investigations.
5-2.2	Summarize the composition of an ecosystem, considering both biotic factors and abiotic factors.
5-2.3	Compare the characteristics of different ecosystems.
5-2.4	Identify the roles of organisms as they interact and depend on one another through food chains and food webs in an ecosystem, considering producers and consumers, decomposers, predators and prey, and parasites and hosts.
5-2.5	Explain how limiting factors affect populations in ecosystems.

Lesson Description:

Students will learn how to determine and compare pH levels by conducting experiments to test the pH level of different solutions.

Focus Questions for Students:

1.	What is pH?
2.	What is an instrument used to measure pH?
3.	What is a pH scale?

Culminating Assessment:

Have students draw and label the pH scale and arrange the sampled liquids on the scale based on their test results.

Materials, Equipment and Resources:

Stream Ecology Overview Information	Stream Ecology Vocabulary List
pH testing strips and color charts (park provides)	watch
50 ml graduated cylinders (park provides)	tap water
50 ml plastic beakers (park provides)	distilled water
orange juice	Coke™
milk

Teacher is to return the kit upon arrival at Table Rock State Park.

Teacher Preparation:

1.	Read overview information and vocabulary list. Be prepared to introduce pH as a chemical property of a liquid.
2.	Collect and label each of the five liquids listed above or any substitutes for students to determine the pH. 3/4 cup to 1 cup of each liquid for each class activity should be a sufficient amount.

Background Information:

Water pH is an indicator of how much acid is in the water. Water pH is important as it plays a role in biological, chemical and physical properties of water. The pH of water determines which plants and animals can live in a body of water as different organisms have different tolerance levels to acidity. pH also affects other chemical properties of water such as the availability of minerals.

The pH scale is used to determine if a solution is acidic or basic based on the pH reading.

0	7	14

acidic	neutral	basic

Procedures:

1.	Discuss with students that pH is a measurement of the acidity in a liquid and how to use the pH scale to determine if a sample is an acid, base, or neutral.
2.	Divide the class into groups of 3-5 depending on class size.
3.	Inform the students what liquids will be tested and have them predict the pH of each sample.
4.	Give each group a graduated cylinder and base, five beakers (one for each liquid), and five pH test strips with a pH color indicator chart.
5.	Have each group collect 30 ml of each of the five liquids in the graduated cylinder and pour the samples over into separate plastic beakers for testing pH. Rinse out the graduated cylinder each time after pouring any liquids that are not water so a residue does not remain that may affect further tests.
6.	Dip one strip of indicator paper into each beaker for at least one minute. Be sure all color segments of the test strip are in the liquid.
7.	Remove the indicator paper strip and compare all the segments to the pH color chart provided. Try to match the chart segment that resembles the test strip colors the best.
8.	Have the students record in their science notes the pH reading they get from each liquid tested. Please rinse out all beakers and graduated cylinders well after completing the activity before the next class' use or returning them to the park.
9.	From the results, have the students predict what the pH will be of the water in Carrick Creek when they test it during their activity at the park.

Teacher Resources/Bibliography:

A River Ran Wild by Lynn Cherry

Differentiation of Instruction:

If there will be children with special needs, English as a second language or gifted & talented, etc. - please contact Table Rock State Park before the visit. These needs can be addressed on an individual basis.