Name: ____________________________________ Date performed: _________ Grade and Section: __________________________ Learning Activity Sheets #7 Acids and Bases Competency: Determine basic and acidic mixtures using natural indicators (S7MT-Ii-6) Objectives: Identify the different properties of acid and base. Differentiate acidic and basic based on universal pH paper. Determine the pH level of different materials. Litmus Paper can be used to test a substance chemically to discover which compound it is. When placed in a sample chemical in the litmus paper will react with the substance and change the paper’s color. Comparing the change litmus paper strip to a chart you can determine where a substance falls on the acid base continuum. Strong acids match the color for 1, 7 is neutral and 14 is a strong base. Test some common materials in this activity. basic Procedure: 1. Label each cup with the name of the substance. Pour a small amount of each into each cup. 2. Dip a strip of litmus paper into the first substance. Did it change color? Compare the strip’s color with the acid-base continuum chart (pH scale level litmus paper chart) and record your findings in the chart below. 3. Repeat the procedure for each substance. Make sure to use a new strip of litmus paper for each substance. Record the pH number of each substance and whether it is acid, base or neutral in the table below. Data Table: Material pH Level number Acis, Base or Neutral 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. Guide Questions: 1. What are the materials that are considered acid? 2. What are the materials that are considered base? 3. Is there material in the activity that is neutral? What is that material? 4. Compare acid and base based on their properties.