PolyToday: Reaction in a bag

The Class of 2024 was hard at work today with a chemistry lab. Students used three common chemicals - sodium bicarbonate (baking soda), Calcium chloride (road salt), and Phenol red dye used as a pH indicator - and mixed them in baggies. The seventh-graders observed the changes in temperature, color, and even changes in state, and by changing one variable at a time, they had a better idea about which substance had contributed to the overall reaction.