Today students learned about endo and exothermic reactions.
Endothermic reactions absorb heat and get warmer (End Up).
Exothermic reactions lose or release heat and get colder (Exit down).
To test this out, students in groups were given a whack-a-pack and asked to make observations. The pack starts off at room temperature and when you hit it, the reaction occurs. This is a chemical reaction for a few reasons - one you can hear it fizzing. Two it blows up so a gas is being formed (1 of the 4 ways you know a chemical reaction has occurred). And Three there is a temperature change (another of the four ways). The pack gets really cold which means it is releasing heat and this is an exothermic reaction.
Watch this little video to see how it works. These are available at Dollar Tree if you are interested.I will try to post some student photos soon.
After this lab demo, students answered questions and then worked on math practice.
Tonight's homework is the Unit 2 Review Sheet (it's tan). The Unit 2 test is Friday. The first Benchmark will be on Tuesday.
"The pack gets really cold which means it is releasing heat and this is an exothermic reaction. "
ReplyDeleteThat is wrong. If it were exothermic, it would feel hot. Being cold means it is ABSORBING heat, and it is an ENDOthermic reaction.