Lesson 9 — Activity 1: Endothermic Reactions
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Lesson 9 — Activity 1:
Endothermic Reactions
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Chemical reactions usually involve the exchange of energy in some form. Endothermic reactions take in energy from the surroundings. In this activity, you will learn about the chemical reaction known as an endothermic reaction.
You might think of chemical reactions as occurring only in labs, but in reality, they occur in the world around us and in our own bodies every day. Most chemical reactions involve the exchange of energy between molecules and compounds. The bonds that hold molecules together contain a tremendous amount of energy. When these bonds are broken, a large amount of energy is released.
An
endothermic reaction occurs when a greater amount of energy is required
to break the existing bonds in the reactants than is released when the
new bonds form in the products. In other words, this means an
endothermic reaction requires or takes in energy. This required energy can be provided in many forms, but it is
typically in the form of heat. That is, endothermic reactions will often
draw heat from their environment in order to take place.
An endothermic reaction occurs when a greater amount of energy is required to break the existing bonds in the reactants than is released when the new bonds form in the products. In other words, this means an endothermic reaction requires or takes in energy. This required energy can be provided in many forms, but it is typically in the form of heat. That is, endothermic reactions will often draw heat from their environment in order to take place.
Here is a list of examples of some endothermic reactions.
- melting ice cubes
- evaporating liquid water
- converting frost to water vapor (melting, boiling, and evaporation in general are endothermic processes)
- baking bread
- melting ice cubes
- evaporating liquid water
- converting frost to water vapor (melting, boiling, and evaporation in general are endothermic processes)
- baking bread
Another example of an endothermic reaction is a cold pack. Cold packs are frequently used by athletes and trainers to treat minor injuries, such as inflammations, sprains, muscle spasms, headaches, etc. Cold packs consist of two separate areas, one containing water and the other containing a salt. When you break the seal between the chambers and shake the pack, the two compartments combine and the salt dissolves in the water. This generates a chemical reaction. Depending on the type of salt, this reaction can absorb heat energy, which is an endothermic reaction.
Click on the Play button below to watch a video about how to cool drinks quickly with an endothermic reaction! Now that's cool!
Click on the Play button below to watch a video about how to cool drinks quickly with an endothermic reaction! Now that's cool!
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