Summer SAVY 2016 (Session 3, Day 2) – Chemical Spill
We had a fun second day of SAVY studying Chemical Spills!, complete with lots of hands-on experiments. Today we discussed a spill of sulfuric acid on an interstate in Florida. In order to understand the chemical (sulfuric acid) involved in the spill, we learned some fundamental properties of acids and bases. We learned both the Arrhenius and Bronsted-Lowry definition of acids and bases, but primarily focused on acids as hydrogen ion donors and bases as hydrogen ion acceptors. We then discussed the pH scale as a measure of how many hydrogen ions are in solution. The students were quick to remember that acids have pH values less than 7 while bases have pH values greater than 7. We discussed multiple ways to determine the pH of a solution (litmus paper, pH paper, pH meter, and indicators).
Next we had fun using red cabbage indicator to create a series of standards, solutions with known pH values that changed colors with addition of the indicator. We then used these solutions in order to determine the pH of a variety of household items. Ask your student to tell you about the pH values of the various items we tested. Finally, we used the indicator to determine the pH of “water samples” collected from around the spill site. Certain samples were taken close to the spill while others were gathered further away from the site of the accident. The students then reasoned, based on the pH of their sample, from where the sample had been taken; they were quick to suggest that the samples with the lowest pH were from right near the acid spill, while those farther away had been diluted some and thus had a higher (closer to neutral) pH. We also tried two different methods to deal with the spill contents—neutralization with base and dilution with water. Consider talking with your child about which one required less volume and which one they would use to clean up this sulfuric acid spill.
We ended the day considering the various people who were involved in the accident and what roles they played in the process. We learned what a hazmat team does and considered how they played a role in the response and what they probably did to clean up the spill in light of the conclusions we drew about returning a solution to neutral pH in our experiment.
Tomorrow we will tackle a new type of chemical spill—stay tuned for more!