Acids, Bases, and the pH Scale

Acids, Bases, and the pH Scale

Author: Sarah Thompson

Students will be able to identify acids and bases by completing the following activities:

  1. Watch and take notes on Acids and Bases Video
  2. Take notes from Powerpoint presentation
  3. Watch and define vocabulary terms from Brainpop video on pH scale
  4. Identifying acids and bases with litmus paper
  5. Creating a pH scale using biology textbook
  6. Determining the pH of a liquid by using pH paper.
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What's an Ion video review

Confused about ions? We'll learn the difference between an atom and an ion. Ions are formed because of a net charge on an atom, because the number of protons and electrons do not balance. This means that the atom is no longer electrically neutral, but is a cation or an anion. We also talk about polyatomic ions.

pH Chemistry Powerpoint

Takes notes from the following powerpoint. The more notes you have in your notebook, the better you will do on the test. If there is anything you do not understand, please ask.

pH Scale Video and Vocabulary

Watch the following video (copy and paste link into new window) and use the attached sheet to define the vocabulary words found in the video. You just need to put the terms and definitions into your notebook. You will have to enter the username and password in order to watch the video.

USERNAME: washoes
PASSWORD: brainpop


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Acids and Bases Lab


You must answer the following questions BEFORE completing the lab. Pre-read the procedures and answer the questions (they are based on the lab itself). This shows me you read the lab before completing the lab. If I do not see pre-lab questions from you, you do not get to complete the lab until you do them.

1. What do double arrows in a chemical reaction mean?

2. Write down the chemical equation for the reaction of water molecules to form ions.

3. Why is water considered neutral?

4. What does the pH scale measure (be specific!!)?

5. What makes a solution acidic?

6. What makes a solution basic?

7. Draw the pH scale and label it the same way as the lab handout.

8. Describe some characteristics for acids. List two examples.

9. Describe some characteristics for bases. List two examples.

10. What pH range must be maintained in order for chemical reactions necessary for life to take place?

Google the answers to the following two questions:

11. What is red litmus paper used to test for? What color will it change to?

12. What is blue litmus paper used to test for? What color will it change to?

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pH Scale Drawing

—Step 1: Obtain one print out of the pH Scale Drawing
—Step 2: Turn to page 43 of your Biology book
—Step 3: Color in your pH Scale the same way using colored pencils
—Step 4: Label the circles as Hydrogen ions Make sure you also include the “High H+ Concentration” boxes as well
—Step 5: Make sure name is on back – we will use these for another activity.

Measuring pH Lab

After you've completed the Acids and Bases Lab and created a pH scale drawing, you will then use your knowledge to determine the pH of various liquids.

Step 1: Using pH testing strips, measure pH of liquid and write answer on handout.
Step 2: Work with your lab partner to answer questions
Step 3: Place each liquid you just tested on your pH scale drawing (activity you completed before this lab)

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