TODAY Put the following table and problem below on a piece of paper Predict a pH level for each substance pH Lab Problem: How acidic or basic are common household substances? Household Substance Predicted pH Actual pH 409 Cleaner lemon juice Tap water mouthwash vinegar Aquarium water

TODAY BELL RINGER Bell ringer pH Lab What is an acid? (A) a compound that releases a hydrogen ion in water (B) a compound that removes a hydrogen ion from water (C) a compound that increases the pH of a solution (D) a compound that produces a buffer in solution What term describes the sugar in a glass of lemonade? (A)solvent (B)solution (C)solute (D)protein

Testing pH Lab Background Information Many substances around your home are acids and have a low pH. Others are bases and have a high pH. In this lab you will use a Vernier LabQuest and pH sensor probe to investigate the pH of several common substances. Problem: How acidic or basic are common household substances? Procedure: Obtain and wear goggles. Record the problem and the following data table in on a piece of paper: Household Substance Predicted pH Actual pH 409 Cleaner lemon juice Tap water mouthwash vinegar Aquarium water

Don’t forget to rinse the pH sensor probe tip with distilled water!!! 3. Before each use of the pH sensor probe, you must rinse the tip of the sensor thoroughly with distilled water. To do this, hold the pH sensor above a rinse beaker and use the rinse bottle to thoroughly rinse the sensor tip. IMPORTANT Do not let the pH sensor probe dry out. Keep it in a 250 mL beaker with about 100 mL of tap water when not in use. The tip sensor is made of glass – it is fragile. Handle with care! 4. Connect the pH sensor probe to the LabQuest. Dip the tip of the pH sensor probe into the beaker or flask containing the sample. Record the pH of the sample in the data table. Rinse the tip of pH sensor probe as described in step 4. Test the next sample and record the pH in the data table. Continue this process for each remaining sample. Don’t forget to rinse the pH sensor probe tip with distilled water!!!

7. On your piece of paper, draw the pH scale shown below: Label the pH scale with the names of the household substances and pH values recorded in your data table. Conclusion:  State the purpose of this lab investigation.  Report the data – the pH values of each substance tested.  Describe the lab methods used to complete this lab. Questions What is the pH range of the solutions you tested? Construct a Venn diagram that classifies each substance as acid, neutral, or base. Describe the hydrogen ion concentration in each of the 6 solutions. How was your predicted pH compared to the actual?

General Biology – use last slide Honors Biology – use previous slide

7. On your piece of paper, draw the pH scale shown below: Label the pH scale with the names of the household substances and pH values recorded in your data table. Conclusion: (in paragraph form)  State the purpose of this lab investigation.  Describe the lab methods used to complete this lab. -What is the pH range of the solutions you tested? -Describe the hydrogen ion concentration in each of the 6 solutions. Household Substance Predicted pH Actual pH 409 Cleaner lemon juice Tap water mouthwash vinegar Aquarium water