This week in Chemistry, the sophomore team has begun a brand new unit with a focus on change in the climate and possible solutions to pollution problems. Students are learning about man-made disasters and what was done—and not done—to solve the problems that arose because of these disasters. This week, students learned about how everyday materials can have harmful effects on the earth and impact our entire global community. We did an interactive reading on acid rain and what happens to areas exposed to it; students then determined which areas are at risk of acid rain exposure.
Students are now comparing these well-known disasters to potential harmful occurrences in the city of Chicago. For example, one landmark in Chicago that could be susceptible to a harmful occurrence is Lake Michigan. If Lake Michigan is exposed to too much acid rain, the pH of the lake could become slightly acidic which would have detrimental effects for the living creatures that inhabit the lake.
After making their comparisons, students participated in a lab where they learned what the pH scale is and what the pH of some substances should be. For this lab, we used soda and cleaning supplies to apply this scientific knowledge to common, everyday substances. Students had to run three different tests on each substance in order to determine its pH and to determine if it was a base or acid. For the first test, they were given red litmus paper. If the red litmus paper turned to a blue color upon contact with the substance, that meant that the substance was a base—which is considered the chemical opposite of an acid. If the red litmus paper stayed red, that meant that the substance was an acid. They were then given blue litmus paper. If the blue litmus paper turned red upon contact, that meant the substance was an acid. If the blue litmus paper stayed blue, that meant that the substance was a base. The third test that they conducted was the pH test. The pH paper would change a color that matched with a number on the pH scale. Students then determined what the substance’s pH reading was and how to rank it. The students enjoyed testing well-known cleaning supplies, drinks, and other household items.