## Reflection: Complex Tasks Boyle's and Charles' Laws - Section 4: Extend

In the Charles' Law lab a lot of students were confused with where the gas was coming from.

As I walked around the classroom questioning students many of them felt that the reason why the balloon got larger was because the water was evaporating to create water vapor which filled up the balloon.

Although this is somewhat part of the answer, it was not what I was looking for.  What I wanted students to understand was that there was air trapped in the flask when the balloon was placed on top.  When the flask was heat, then the balloon inflated because the air that was trapped heat up, so if temperature increases so does volume.

I could avoid this confusion with the water if I did not have them put the water in the bottom of the flask; however, heating a flask on a hot plate with not liquid inside is not a very good idea as that it is likely to crack.  Nonetheless I still like this activity, I just need to make sure that I talk to each group about the activity as I walk around the classroom.  This is a video which shows how I do this.

Complex Tasks: Confusion with Balloon Lab

# Boyle's and Charles' Laws

Unit 6: Unit 7: Earth's Atmosphere
Lesson 3 of 9

## Big Idea: Boyle's Law describes the inverse relationship between pressure and volume while Charles' Law describes the direct relationship between temperature and volume.

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Subject(s):
Science, Chemistry, climate, atmosphere (Science), boyle's law, Charles' Law, Gas Laws, Gases, radiation
105 minutes