NAME ______

Boyle’s Law with Bell Jars

Materials: bell jar apparatustubing with valvessmall balloonspennies

syringemarshmallowscotton balls

Safety: Goggles required

No Horseplay!

Severe injury will result from evacuating the chamber while in contact with skin.

The bell jar should ONLY be used with the bottom plate provided.

Procedure:

  1. Have someone gently push down on the bell jar to make certain that the bell jar is pressing against the seal of the base. While they are doing this, pull the piston of the syringe out to the 60 ml mark.
  1. Where does the air come from that fills the syringe?______

______

  1. Let go of the piston, and watch what happens. Now quickly push the piston all the way back into the syringe. Listen for the sound of moving air.
  1. Where did the air go that was in the syringe?______

______

  1. Describe in words the amount of force needed to pull out the piston.______

______

  1. Repeat these steps five times:

- pull the piston out to the 60 ml mark

-let go of the piston and see what happens

-push the piston all the way back in

7. As you followed the steps in # 6 above, what happened to the amount of force needed?______

______

  1. Did the pressure INSIDE the bell jar increase, decrease or stay the same during step 6?

______

  1. SLOWLY turn the valve at the top of the bell jar to release the vacuum. Then place the valve back on the bell jar with light finger pressure and a half turn. DO NOT OVER TIGHTEN.

Chapter 14: The Behavior of Gases

Balloons

PREDICT:

Predict what will happen to the volume of a balloon ifthe air is pumped out of the bell jar using a syringe. Explain your predictions using complete sentences. You may also include drawings.

______

OBSERVE:

  1. Put a partially inflated balloon on the bottom plate and place the bell jar over the plate. Pump the air out of the bell jar using the syringe.
  2. Observe any changes to the balloon.
  3. SLOWLY turn the valve at the top of the bell jar to release the vacuum. Observe any changes to the balloon then remove it from the bell jar.
  4. Describe your observations of the balloon using complete sentences. You may also include drawings.

______

______

EXPLAIN:

Propose a possible explanation for your observations. Use complete sentences.

______

REVISED EXPLANATION (RE-POE)

Revise your explanation based on the class discussion following the activity. Use complete sentences.

______

Chapter 14: The Behavior of Gases

Marshmallows

PREDICT:

Predict what will happen to the volume of a marshmallow ifthe air is pumped out of the bell jar using a syringe. Explain your predictions using complete sentences. You may also include drawings.

______

OBSERVE:

  1. Put a marshmallow on the bottom plate and place the bell jar over the plate. Pump the air out of the bell jar with the syringe.
  2. Observe any changes to the marshmallow.
  3. SLOWLY turn the valve at the top of the bell jar to release the vacuum.
  4. Observe any changes to the marshmallow then remove it from the bell jar. DO NOT EAT THEM. THEY WILL BE CONTAMINATED!
  5. Describe your observations of the marshmallow using complete sentences. You may also include drawings.

______

EXPLAIN:

Propose a possible explanation for your observations. Use complete sentences.

______

REVISED EXPLANATION (RE-POE)

Revise your explanation based on the class discussion following the activity. Use complete sentences.

______

Chapter 14: The Behavior of Gases

Cotton Balls

PREDICT:

Predict what will happen to the volume of a cotton ball if the air is pumped out of the bell jar using a syringe. Explain your predictions using complete sentences. You may also include drawings.

______

OBSERVE:

  1. Put a cotton ball on the bottom plate and place the bell jar over the plate. Pump the air out of the bell jar.
  2. Observe any changes to the cotton ball.
  3. SLOWLY turn the valve at the top of the bell jar to release the vacuum.
  4. Observe any changes to the cotton ball then remove it from the bell jar.
  5. Describe your observations of the cotton ball using complete sentences. You may also include drawings.

______

______

EXPLAIN:

Propose a possible explanation for your observations. Use complete sentences.

______

REVISED EXPLANATION (RE-POE)

Revise your explanation based on the class discussion following the activity. Use complete sentences.

______

Chapter 14: The Behavior of Gases

Penny

PREDICT:

Predict what will happen to the volume of a penny if the air is pumped out of the bell jar using a syringe. Explain your predictions using complete sentences. You may also include drawings.

______

OBSERVE:

  1. Put a penny on the bottom plate and place the bell jar over the plate. Pump the air out of the bell jar.
  2. Observe any changes to the penny.
  3. SLOWLY turn the valve at the top of the bell jar to release the vacuum.
  4. Observe any changes to the penny then remove it from the bell jar.
  5. Describe your observations of the penny using complete sentences. You may also include drawings.

______

______

EXPLAIN:

Propose a possible explanation for your observations. Use complete sentences.

______

REVISED EXPLANATION (RE-POE)

Revise your explanation based on the class discussion following the activity. Use complete sentences.

______

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