I was asked to bring something into class with a pressure less than 1.0 atm, after researching i found out that if I heated a bottle it will shrink and therefore this bottle will have the needed pressure. the problem is that after I put the bottle inside the microwave for 1 or 2 minutes nothing happened to it. so today i got to school and one of my teachers just crushed the bottle and put the cap in itand say it had less than 1atm is this right?

Question

I was asked to bring something into class with a pressure less than 1.0 atm, after researching i found out that if I heated a bottle it will shrink and therefore this bottle will have the needed pressure. the problem is that after I put the bottle inside the microwave for 1 or 2 minutes nothing happened to it. so today i got to school and one of my teachers just crushed the bottle and put the cap in itand say it had less than 1atm is this right?

Yes. If you place a plastic bottle in the microwave, it didn't get much heat. Neither air nor plastic absorbs much in the way of microwaves in an oven; therefore, you had no heating. What the teacher did was to push the air OUT of the bottle, while holding the bottle crimped then the teacher placed the cap back on, the air can't get back IN, so there is less than 1 atm pressure in the bottle. Clever, huh?

Answer 1

Yes, what your teacher did is an effective way to create a container with pressure less than 1.0 atm. By crushing the bottle and sealing it with the cap, the air inside the bottle is compressed and cannot escape. This compression reduces the volume of the air, resulting in a lower pressure inside the bottle than the atmospheric pressure outside.

To further explain how this works:

1. When the bottle is crushed, the volume of the air inside decreases.
2. According to Boyle's Law, when the volume of a gas decreases, its pressure increases, and vice versa, as long as the temperature remains constant.
3. By sealing the bottle with the cap, the air inside is trapped, preventing it from expanding back to its original volume.
4. As a result, the pressure inside the bottle is lower than the atmospheric pressure outside.

It's important to note that heating the bottle in the microwave was not an effective method because plastic and air do not absorb much microwave radiation. Therefore, there was not enough heat generated to cause a significant change in pressure inside the bottle. The method used by your teacher is a more reliable way to achieve the desired result of having a container with pressure less than 1.0 atm.