Catchy Title: Raindrops Keep Burning On My head
Theme/Topic of Lesson: pH and Acid Rain
Time Commitment: Two 90-minute periods/blocks
Science - Chemistry
Science - Physical sciences
Grade Level(s): 6,7,8
Class Challenge Question: When is acid rain harmful?
Acid rain, or acid precipitation, refers to any precipitation having a pH value less than that of normal rainwater. Atmospheric carbon dioxide (CO2) combines with water to form carbonic acid (H2CO3), commonly known as carbonated water. The pH of carbonic acid generally ranges from 5.0 to 5.6. As a result, normal rainfall is acidic. Rainfall with a pH of 5.6 or higher is considered normal and rainfall with a pH below 5.6 is considered acid rain. Acid rain readings in the northeastern United States have often been in the range of 4.0 to 4.6. Acid precipitation can also occur as snow, sleet, hail, dew, frost and fog.
Acid precipitation can be a costly problem. It is estimated that the cost of the damage resulting from the effects of acid precipitation in the United States alone runs into the millions of dollars annually. Acid precipitation is also a suspected killer of ponds, streams, trees and wildlife.
This lesson allows students to learn about the concept of pH and to begin to think about and appreciate the impact that acid rain has on the environment and human health.
Acid precipitation can compromise the integrity and well-being of an ecosystem and its inhabitants.
- As the pH of water nears 6.0, insects and plankton begin to disappear.
- Below the pH of 5.0, the water is largely devoid of fish and is considered to be dead.
- Animals dependent on aquatic ecosystems begin to be affected through damage to the food chain.
- Terrestrial plant life is negatively affected due to the increased acidity. Forests have also been labeled dead due to the extensive foliage damage.
- Studies indicate a link between acid precipitation and respiratory problems in children and asthmatics.
- Acid precipitation can increase the availability of some toxic elements such as aluminum, copper and mercury.
In this two day lesson students will test the pH of some common household items and place them correctly on a pH scale. Once students understand the pH scale and how it is used to rate solutions according to how acidic or basic they are, they will investigate the impacts of acid solutions on the environment and human health by using the Internet.
Students will work with a partner for both parts of the lesson. During the laboratory investigation of common household items, students will need to be mindful of safety and wear goggles at all times. The teacher should select the working pairs so that each student has the opportunity to perform the investigations and participate in the Internet search.
|Maryland Content Standards|
Students will use scientific skills and processes to explain the composition, structure, and interactions of matter in order to support the predictability of structure and energy transformations.
|Maryland State Indicators|
distinguish one substance from another based on observable and measurable properties (i.e., density, boiling point, melting point). (MLO 4.1.)
|Maryland Content Standards|
Students will use scientific skills and processes to explain the interactions of environmental factors (living and non-living) and analyze their impact from a local to a global perspective.
|Maryland State Indicators|
analyze how human activities can accelerate or magnify many naturally occurring changes (i.e., erosion, air and water quality, populations). (MLO 6.2.)
|Technology productivity tools|
|ISTE Technology Standards|
3. Technology productivity tools
Students use technology tools to enhance learning, increase productivity, and promote creativity.
Students use productivity tools to collaborate in constructing technology-enhanced models, prepare publications, and produce other creative works.
|ISTE Technology Performance Indicators|
Use content-specific tool
Use content-specific tools, software, and simulations (e.g., environmental probes, graphing calculators, exploratory environments, Web tools) to support learning and research.
The Students will:
- Test the pH of common household solutions
- Understand and explain the pH scale
- Understand and explain the causes and impact of acid percipitation
Though students will work cooperatively in pairs for both of the tasks in this lesson, they will be assessed by the information provided in their Lab Data Sheet and in the Internet Data Sheet.
Per student team/group of 2
- Computer with Internet access
- 8 beakers, clear cups, or glasses (baby food jars also work well)
- pH paper (Hydrion Paper) and color chart - at least 10 pieces
- 5 mL vinegar
- 5 mL distilled water
- 5 mL lemon juice
- 5 mL orange juice
- 5 mL ammonia
- 5 mL cola
- 5 mL carbonated non-cola
- 5 mL milk
- 10 mL graduated cylinder
- stirring rod or spoon
- Design Your Own Experiment (View)
- Internet Data Sheet Web Quest (View)
- Lab Data Sheet and Answers (View)
- You Predict (View)
- Acid - Compound that releases hydrogen ions in solution
- Base - Compound that can remove a proton from an acid
- Acid Rain - rain that has a pH greater than 5.6. Formed when air-borne pollutants combine with water vapor
- pH Scale - measurement system that ranges from 0 to 14 and indicates the relative acidity (hydrogen ion concentration) and alkalinity (hydroxide ion concentration) of a substance.
- Distilled Water - pure water, without impurities, registers 7.0 on the pH scale
Students will construct meaning in this lesson by using an inquiry approach to the challenge question “When is acid rain harmful?” Students initially will be asked to classify several common solutions or foods as acids or bases. Then the teacher will lead the students to the question “What are acids and bases and how are they measured?” The students’ questions will be answered through an experiment to determine the pH of some common household items. From this point the teacher will remind the students of the challenge question for the lesson and ask how this first activity has helped them answer the challenge question. Students should recognize that they now have the background knowledge on acids that will be required to investigate what is acid rain and what are its impacts on the environment and human health. To facilitate this line of inquiry the students will use the Internet to investigate acid rain and its effects. Then the students will design their own experiment to be conducted using authentic data from the Internet to answer a question of their choice in relation to the challenge question.
Students will work in pairs throughout the lesson. This will require that a computer lab with Internet access be available for the second day of the lesson.
1: Laboratory Investigation
Daily Challenge Question: What is an Acid?
Set-up Directions: 2,3: Internet and Laboratory Investigations
For today's lesson the teacher needs to have sufficient copies of the Lab Data Sheet and the You Predict worksheet available for each student. Also, the equipment necessary for the laboratory investigation should be placed in a central location free from physical obstacles so that students can get their materials easily and safely. These materials include pH paper, vinegar, distilled water, lemon juice, ammonia, orange juice, beverages (cola, carbonated non-cola, milk), 10 mL graduated cylinder, 8 small beakers, clear cups or glasses, and 1 clean stirring rod or spoon. Goggles should be pre-sterilized with UV light before student use.
Teacher Presentation & Motivation:
To get students interested in the topic of this 2 day lesson the teacher should pose the challenge question, "When is acid rain harmful?" The teacher should accept some answers to the question and as soon as the opportunity arises, (probably with the first response if acid rain is mentioned in the response) ask "What is acid rain?" As a student begins to answer the question by using the word "acid" the teacher should ask "What is an acid?" and so on until the stage has been sufficiently set for an investigation.
The teacher will have to explain the pH scale prior to Activity 2. See teacher background information for assistance.
Activity 1 - You Predict
The teacher should distribute the You Predict worksheet to each student and allow 2-3 minutes for them to predict individually which items are acids and which are bases. Then allow 2-3 minutes for students to compare their predictions with their neighbor. Students should discuss why they predicted as they did. Provide an explanation of the pH scale to help reinforce the terms "acid" and "base". Do not give the answers to this sheet at this point. Inform students that they will find the answers in their Lab and Internet investigations.
Activity 2 - Lab Data Sheet
The teacher should instruct the students to wear goggles at all times during the laboratory and to wash their hands when finished. Distribute the Lab Data Sheet and explain where all of the materials are located and how they should be disposed of once finished the laboratory. Allow students to work in pre-assigned laboratory pairs but have each student record their own data and answer the questions on their own worksheet.
To bring closure to the day's lesson ask students to look at their You Predict worksheet and share what items on the list were tested today. Were they acids or bases? What is an acid? Is a pH of 4 an acid or a base? Etc.
Daily Challenge Question: When is acid rain harmful?
For today's lesson the teacher needs to have sufficient copies of the Internet Data Sheet and the Design Your Own Experiment worksheet available for each student. Internet access should be made available in the classroom or in a computer lab for students to work in pairs.
Teacher Presentation & Motivation:
The teacher will need to have access to a computer lab with Internet access for the day's lesson. Also sufficient copies of Internet Data Sheets and Design Your Own Experiment for each student should be copied prior to the lesson.
Again, the teacher should begin the day by reminding the students of the Challenge Question, "When is acid rain harmful?" Allow students to share ideas as yesterday. This should solidify the background knowledge on acids and pH that was instructed on the previous day. Tell students they will use the Internet to find out what impact acid precipitation has on the environment, people, animals, buildings, etc.
Activity 1 - Internet Data Sheet
Complete the internet data sheet
Focus for Media Interaction
Focus for Media Interaction: The focus for media interaction is a specific task to complete and/or information to identify during or after viewing of video segments, Web sites or other multimedia elements.
The focus for viewing the websites on the Internet Data Sheet is to provide students background information on acid rain and how it impacts animals, people, the environment and structures. Additionally, students will become familiar with retrieving
archived data from the Internet and applying it to their own prior knowledge to answer questions concerning acid rain and its distribution throughout the United States.
What will your students be responsible for while viewing this piece of multi-media or video?
The teacher should distribute the Internet Data Sheet and allow students to work with the same partner as they worked with on the previous day. The teacher should facilitate by acting as a guide or coach as needed.
Post Viewing Activities
How will students utilize the information they gathered while viewing the multi-media or video?
In order to apply the information gleaned from the laboratory investigation and the Internet search, students will design an experiment which will be carried out using authentic data from the Internet. Students will follow the directions on the Design Your
Own Experiment activity sheet. The teacher should facilitate student pairs as they develop their experimental question, but allow them the freedom to choose what to study and how to collect the data.
To bring closure to the day's lesson ask students share some of their responses to the Challenge Question and revisit the You Predict sheet to make sure all students have found the remaining answers.
Families can contact their local power company. Many power companies use more than one source of power to make enough electricity for the community. Some also buy electricity from other power companies. Ask the power company which is its primary source (hydroelectric, nuclear, gas, oil, coal, other) and what other sources it uses. If they can tell you, find out what percent of their output is generated by each source. If your company buys from other companies ask if they know what source generates that company's electricity. Using this information,
discuss how your use of electricity impacts the acid precipitation problem.
- Locate or list energy efficient buildings in your community. Contact a local architect or an architecture department in a local college or university and invite an architect to visit your classroom to describe how homes, schools, and office
buildings can use energy more efficiently.
- Visit a local cemetery and observe the wearing away of the headstones or other grave markers over time. Military cemeteries use limestone markers which are more easily affected by acid rain than the granite markers in some private cemeteries. Can you tell by the dates on the marker stones and the condition of the
stones which ones acid rain may have damaged? Remember that these materials would naturally deteriorate when exposed to the weather and rain (even clean rain). Acid rain would accelerate this damage.
- Contact a local natural resource specialist from your local zoo or park and ask that person to tell you about the impact, if any, of both acid rain and dry deposition in the lakes, forests, or other natural resources in your area.
- Language Arts
Students could write a poem about acid rain and its impact on trees, people, buildings, etc.
- Fine Arts
Students could make posters to help people visualize the impact of acid precipitation.
- Social Studies
Students can study the events that led to the increasing acid precipitation problem in the United States and around the whole.
Students can create a PowerPoint presentation describing all that they have learned from this lesson.
As a reflective practitioner, note how this lesson could be adjusted after its initial implementation. How successful were the students? What did the assessment demonstrate about the students’ learning? What skills do the students need to revisit? What instructional strategies worked and what made them successful? What will you change the next time you use this lesson? Why?
Author: Howard Shindler and Rosetta Jackson
Modified by: Laura Corbin Frazier