Chemical Reactions Absorption and Release of Thermal Energy

Students are challenged to design cold packs for treating injuries. To do this they must find a chemical reaction that absorbs heat energy. The ideal chemical reaction will reach a temperature in the range of 0°C to 4°C and maintain that temperature for a minimum of 20 minutes. Based on the information provided in the table, and a room temperature of 25°C, which reaction best fits the criteria of the design challenge?

• 1

• 2

• 3

• 4

Tags

NGSS.MS-ETS1-1

NGSS.MS-ETS1-2

NGSS.MS-PS3-3

NGSS.MS-PS3-4

Meals-ready-to-eat (MREs) are packaged meals that include their own disposable heat pack to warm the food. Students are challenged to duplicate MREs in the science classroom using chemical reactions. The final product must be safe and light. Based on the observations, which chemical reaction would be the best choice for making a heat pack?

• 1

• 2

• 3

• 4

Tags

NGSS.MS-ETS1-1

NGSS.MS-ETS1-2

NGSS.MS-PS1-2

NGSS.MS-PS3-3

NGSS.MS-PS3-4

Two chemicals are combined in a beaker and react. What data would provide the best evidence for determining if the reaction absorbed or released thermal energy?

• The masses of the substances before and after the reaction

• The temperature inside the beaker before and after the reaction

• Whether or not light and sound were produced during the reaction

• How long it took for the reaction to take place once the chemicals combined

Tags

NGSS.MS-PS1-4

NGSS.MS-PS3-4

Students are asked to design a device that uses a chemical reaction that absorbs heat energy in order to chill a beverage. The criteria for the design challenge as provided by the teacher are listed below.

The chemical reaction must meet the following criteria: •Produce a drop in temperature of at least 15°C

•Require no more than 50 grams total of reactants

•Result in products that are not harmful

•The reaction should happen in less than one minute

One group of students finds that by combining 30 grams of one substance with 25 grams of another substance, they can produce a drop in temperature of 18°C in about 30 seconds. The only product of the reaction is water. This group of students need to redesign their product because they have failed to meet which of the design challenges?

• Produce a drop in temperature of at least 15°C.

• Require no more than 50 grams total of reactants.

• Result in products that are not harmful.

• The reaction should happen in less than one minute.

Tags

NGSS.MS-ETS1-1

NGSS.MS-ETS1-2

NGSS.MS-PS1-6

NGSS.MS-PS3-3

In a certain chemical reaction, Reactant 1 and Reactant 2 release thermal energy. Students collect data by measuring the temperature change produced by adding increasing amounts of Reactant 2 to 25 grams of Reactant 1. They graph the data. Students must design a device that uses 25 grams of Reactant 1 and produces the maximum amount of heat with the smallest amount of Reactant 2. How much of Reactant 2 should they use to meet the criteria of the design challenge?

• 10 grams

• 15 grams

• 20 grams

• 25 grams

Tags

NGSS.MS-ETS1-1

NGSS.MS-PS1-2

NGSS.MS-PS3-3

NGSS.MS-PS3-4

A process that leads to the transformation of one set of chemical substances to another

• Reactants

• Products

• Chemical Reaction

• Chemical Process

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

The method of changing one or more chemical compounds

• Reactants

• Products

• Chemical Reaction

• Chemical Process

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

The substances initially involved in a chemical reaction

• Reactants

• Products

• Chemical Reaction

• Chemical Process

The substances that are yielded from a chemical reaction

• Reactants

• Products

• Chemical Reaction

• Chemical Process

Tags

NGSS.MS-PS1-2

The total kinetic energy of the tiny particles that make up matter

• Reactants

• Products

• Chemical Reaction

• Thermal Energy

Tags

NGSS.MS-PS1-4

NGSS.MS-PS3-4