Household Acids and Bases

Veasley, Joyce Nansen Elementary

Objectives: 1. The learners will be able to determine whether a substance dissolved in water will form an acid, a base or a neutral solution. 2. The learners will be able to infer the presence of acids or bases from evidence in the demonstration of interactions of common household products and an indicator. Apparatus Needed: 1. Egg Cartons (one for every two students) 2. Litmus Paper (red and blue) 3. 10 Household solutions: a. lemon juice b. bleach-water c. water d. aspirin-water e. milk f. ammonia-water g. tea (concentrated) h. vinegar-water i. soap-water j. your saliva 4. 10 Eye Droppers 5. 10 Small Containers, or Clear Cups 6. Red Cabbage 7. 100 mL Water 8. 8 Test Tubes 9. Tube 1. 10 mL of Lemon Juice 10. Tube 2. 10 mL of White Vinegar 11. Tube 3. 10 mL of Boric Acid Solution 12. Tube 4. 10 mL of Water 13. Tube 5. 10 mL of Sodium Bicarbonate Solution 14. Tube 6. 10 mL of Borax Solution 15. Tube 7. 10 mL of Washing Soda Solution 16. Tube 8. 10 mL of Drain Cleaner 17. Test Tube Holder 18. Beakers, 100 and 250 mL 19. Burner Recommended Strategy: Place solutions of a-i in small cups numbered 1-10. Make a testing board by numbering egg carton cups 1-10. Place 5 drops of each solution in the corresponding numbered egg carton cup. Test each solution with the red and blue litmus paper. Record your results on a chart for comparison. Prepare a solution of red cabbage by placing enough red cabbage to fill a 250 mL beaker one-fourth full. Add about 100 mL of water and boil until the solution turns deep purple. Cool. Pour off the liquid. This is the indicator solution. Pour 3 mL of indicator solution in each of the 8 test tubes. Add the solutions listed in apparatus section of writing (test tube #1-8). Mix contents in each tube with a stirring rod. Observe the gradual color change. Determine the pH value of solutions tested using pH paper. You might prepare some unknowns for the students to determine the pH values. Put a chart on the blackboard for them to record their data for class comparison. Several other natural indicators can be used for this activity: beet juice, carrot juice, grape juice, blueberry juice, and flowers, including the blue iris, purple dahlia, and purple hollyhock.
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