Chemistry Name ______Mr. B Date ______Block ______

Circuit Lab – Gas Laws

Station1: Can-Crushing Experiment

Background: The current U.S. 12 oz soft drink can measures about 6.6 cm (2.6 inches) in diameter and 12.1 cm (4.75 inches) tall. The area of a cylinder of these dimensions is about 316 cm 2 (49 in 2), including the ends. The force of one atmosphere of pressure on that area is about 3200 newtons (720 lbs). Nevertheless, such cans can be made of very thin aluminum because the same force acts outward from the inside of the can

If a few cubic centimeters of water is poured into such a can (just enough to cover the bottom) and the can be placed on a laboratory hot plate, the water can be brought to the boiling point where its vapor pressure is equal to atmospheric pressure. The vapor will then push most of the air out of the can. If the can is quickly inverted into a ice-water bath, sealing off the opening, the sudden drop in vapor pressure will result in enough net inward pressure to quickly crush the can.

Materials: Aluminum pop can Bucket of cold water Hotplate Safety glasses Oven mitt (or equivalent)

Procedure: 1. Measure the height and diameter of the can. Make a note of this information on the activity sheet. 2. Fill the can with water and measure the volume of the water by pouring the content from the can using a graduated cylinder. 3. Put a small amount of water in the bottom of the can, just enough to cover the bottom. 4. Wearing goggles and an oven mitt, place the can on the hot plate (heat source). Do so until there is a good chimney of steam coming out the opening in the can. This might take a couple of minutes. 5. Quickly invert the can into an ice water bath and watch the results. 6. Complete the questions on the activity sheet.

Station2: Does Air Have Mass

Background: Mass is a measurement of the amount of matter in a sample, while volume is a measurement of the space occupied by a sample of matter. Mass measurements are made on different types of balances. An electronic balance is commonly used because it gives fast results on a digital display.

Materials: Bell Jar Apparatus Electronic balance Safety glasses

Procedure: 1. Placed the Bell Jar on the host plate and push the syringe plunger in and out several times, until the air has been removed from the Bell Jar. 2. Placed the complete apparatus on the scale and record the mass of the empty container on the data chart. 3. Allow air into the Bell Jar by gently pulling the “H” fitting out of the host plate. 4. Placed the complete apparatus on the scale and record the mass of the container on the data chart and record the mass of the apparatus. Record the mass on the data sheet.

Station3 Balloon in a Bell Jar

Background: A partially filled balloon is placed into a vacuum chamber. When the vacuum is turned on the pressure exerted on the balloon decreases and when the air is allowed back into the jar it will affect the balloon. This is a great example of Boyle's Law which shows an indirect relationship between pressure and volume.

Materials Bell jar Vacuum pump Safety Glasses Small balloons, partially inflated to the same size

Procedure 1. Partially inflate a balloon and put into the Bell Jar. 2. Evacuate the air out of the bell jar by placing the Bell Jar on the host plate and moving the syringe plunger in and out several times. 3. Turn the Bell Jar upside down and continue to evacuating the air from the Bell Jar . 3. Complete questions on activity sheet. 4. Release the vacuum by gently pulling the “H” fitting out of the host plate so that the apparatus is ready for the next group.

Chemistry Name ______

Mr. B Date ______Block ______

Circuit Lab – Gas Laws Station1: Can-Crushing Experiment

1. The volume of the can before heating

2. The volume of the can after heating

3. The amount of volume lost.

Analysis:

Explain what happened in order for the can to be crushed: ______

Station2: Does Air Have Mass Observations :

What occurred inside the bell jar when the piston of the syringe was pushed back and forth?

What was the mass of the apparatus in step 3? What occurred inside the bell jar when the hose was loosened at connection H?

What was the mass of the apparatus in step 5?

Analysis:

Does air have mass? Explain your answer.

______

______

______

______

Station3 Balloon in a Bell Jar Observations:

What happened to the volume of the balloon when you pulled the volume of the syringe to 60 mL?

Analysis:

1. Give an explanation to account for your observations inside the apparatus, including the relationship between variables (volume and pressure).

______

______

2. What law describes the relationship between pressure and volume?

______

3. What is the formula for this law? ______