ALEX Resources

   View Standards     Standard(s): [SC2015] PS8 (8) 7 :

7 ) Design, construct, and test a device (e.g., glow stick, hand warmer, hot or cold pack, thermal wrap) that either releases or absorbs thermal energy by chemical reactions (e.g., dissolving ammonium chloride or calcium chloride in water) and modify the device as needed based on criteria (e.g., amount/concentration, time, temperature).*

This lesson begins with a story about rescuing reptile eggs from a new construction site. Using the story as motivation, students are presented with an engineering design challenge: Build a portable device that can warm, support, and protect one reptile egg as it is moved from a construction site to a nearby reptile conservation center. After observing different heat packs, students discuss the criteria and constraints related to designing a heat pack as the basis for their device. Students investigate calcium chloride as an exothermic dissolver and then move on to calcium chloride and baking soda as the exothermic chemical reaction which will serve as the heat source for their device.

Students adjust the amounts of the reactants (water, calcium chloride, and baking soda) to achieve the right temperature range and then test a prototype in a sealed zip-closing plastic bag. Students use their findings and ideas about insulation and heat transfer to draw an optimized design that 1) Keeps an egg at the ideal temperature, 2) Holds an egg in the proper orientation, and 3) Protects the egg from impact. Each student or student group draws this device and explains how the device meets each of the three criteria.

   View Standards     Standard(s): [SC2015] (5) 4 :

4 ) Investigate whether the mixing of two or more substances results in new substances (e.g., mixing of baking soda and vinegar resulting in the formation of a new substance, gas; mixing of sand and water resulting in no new substance being formed).

[SC2015] PS8 (8) 7 :

7 ) Design, construct, and test a device (e.g., glow stick, hand warmer, hot or cold pack, thermal wrap) that either releases or absorbs thermal energy by chemical reactions (e.g., dissolving ammonium chloride or calcium chloride in water) and modify the device as needed based on criteria (e.g., amount/concentration, time, temperature).*

This lesson is the first of a three-part series on energy transformation. All three lessons have the general purpose of increasing students' understanding of energy transfer, its role in chemical change, and the factors that can influence this change. This lesson is intended to increase students' understanding of heat and chemical reactions. Students will perform an experiment in which you will determine how the temperature of water changes when it is mixed with either calcium chloride or ammonium nitrate.

   View Standards     Standard(s): [SC2015] (5) 3 :

3 ) Examine matter through observations and measurements to identify materials (e.g., powders, metals, minerals, liquids) based on their properties (e.g., color, hardness, reflectivity, electrical conductivity, thermal conductivity, response to magnetic forces, solubility, density).

[SC2015] PS8 (8) 7 :

7 ) Design, construct, and test a device (e.g., glow stick, hand warmer, hot or cold pack, thermal wrap) that either releases or absorbs thermal energy by chemical reactions (e.g., dissolving ammonium chloride or calcium chloride in water) and modify the device as needed based on criteria (e.g., amount/concentration, time, temperature).*

This lesson is the second of a three-part series on energy transformation. All three lessons have the general purpose of increasing students' understanding of energy transfer, its role in chemical change, and the factors that can influence this change. This lesson is intended to increase students' understanding of electron transfer and its role in chemical changes. In groups, students will complete a lemon battery experiment. Students should work in pairs to make a single lemon battery. Then, the student pairs should form larger groups to test batteries comprised of more than one lemon.