It introduces the concept of electron exchange and briefly explains exothermic and endothermic reactions. This is the first in a series of modules on chemical reactions.
This resource is for English Language Learners or English Learners to help them visualize new vocabulary to increase depth of learning.
Students investigate the endothermic reaction involving citric acid, sodium bicarbonate and water to produce carbon dioxide, water and sodium citrate. In the presence of water [H2O], citric acid [C6H8O7] and sodium bicarbonate [NaHCO3] (also known as baking soda) react to form sodium citrate [Na3C6H5O7], water [H2O], and carbon dioxide [CO2]. Students test a stoichiometric version of the reaction followed by testing various perturbations on the stoichiometric version in which each reactant (citric acid, sodium bicarbonate, and water) is strategically doubled or halved to create a matrix of the effect on the reaction. By analyzing the test matrix data, they determine the optimum quantities to use in their own production companies to minimize material cost and maximize CO2 production. They use their test data to "scale-up" the system from a quart-sized ziplock bag to a reaction tank equal to the volume of their classroom. They collect data on reaction temperature and CO2 production.
Students learn how common pop culture references (Harry Potter books) can relate to chemistry. While making and demonstrating their own low-intensity sparklers (muggle-versions of magic wands), students learn and come to appreciate the chemistry involved (reaction rates, Gibb's free energy, process chemistry and metallurgy). The fun part is that all wands are personalized and depend on how well students conduct the lab. Students end the activity with a class duel a face-off between wands of two different chemical compositions. This lab serves as a fun, engaging review for stoichiometry, thermodynamics, redox and kinetics, as well as advanced placement course review.