# Magic Marshmallows

Magic Marshmallows

Learning Target:

Students will predict and observe how volume affects the pressure of gasses.

Materials:

1 syringe

3 mini marshmallows

Procedures:

1.     Gather materials

2.     Pull syringe out so that the black rubber stopper measures 10 mL of air.

3.     Use your finger to cover the opening to prevent any air from escaping.

4.     Decrease the volume inside the syringe by pushing the black rubber stopper down.

What do you observe as you decrease the volume?

How far does the black rubber stopper go?

Was it easy or hard?

Did the pressure inside increase or decrease?

5.     Remove your finger and pull the syringe out so that the black rubber stopper measures 10 mL of air.

6.     Use your finger to cover the opening to prevent any air from escaping.

7.     Increase the volume inside the syringe by pulling the black rubber stopper out.

What do you observe as you increase the volume?

How far does the black rubber stopper go?

Was it easy or hard?

Did the pressure inside increase or decrease?

8.     Pull the syringe apart.

9.     Place one mini marshmallow inside the syringe.

10. Replace the handle of the syringe and push it in as far as it will go without touching the marshmallow.

Make a prediction: What do you think will happen to the marshmallow if the volume around it increases?

11. Use your finger to cover the opening to prevent any air from escaping.

12. Increase the volume inside the syringe.

What do you observe happening to the marshmallow?

13. Pull the syringe apart.

14. Place one marshmallow inside the syringe.

15. Replace the handle of the syringe and pull it out so that the black rubber stopper is at 20 mL.

Make a prediction: What do you think will happen to the marshmallow if the volume around it decreases?

16. Use your finger to cover the opening to prevent any air from escaping.

17. Decrease the volume inside the syringe?

What do you observe happening to the marshmallow?

Draw a picture to illustrate what happened to the marshmallow inside the syringe.

Before:

Increased Volume:

Decreased Volume:

Ticket Out the Door: Explain how the volume affects the pressure of a gas.