Lab 14: Gas Properties and Laws

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For a change of pace this week we are going to do a series of activities and record our results and observations. After we are done, we are going to figure out how the gas properties and laws we learned from the lesson apply to our observations.

Experimental Title: Lab 14:  Investigation Into The Gas Laws

Date of laboratory:  Sept 2, 2014

Purpose:  The purpose of this laboratory is to examine air pressure, Boyle’s Law, Charles’s Law, and the Ideal Gas Law.

Introduction:

  1. Boyle’s Law relates pressure and volume
  2. Charles’s Law relates volume and temperature
  3. Avogadro’s Law relates volume and moles
  4. Ideal Gas Law combines these laws into the formula PV = nRT, where R is the constant 0.0821 L-atm/mol-K

Materials:

  • Empty soda can
  • Wire mesh
  • Stove
  • Oven mitts
  • Tongs
  • Ice
  • Bowl to hold ice water
  • Glass bottles or flasks
  • Wine vacuum pump with rubber stopper
  • Water balloons
  • Regular latex balloons
  • Boiled egg
  • Matches
  • Strip of paper
  • Food coloring
  • Metric ruler
  • Tap water
  • Pipette, thin stem
  • Beaker
  • Textbooks, hardcover, 6–8
  • Clamp
  • Sharpie pen
  • Measuring tape
  • Hair dryer
  • Hand boiler
  • Kitchen scale

Special safety concerns for Lab 14:

  • If anything spills, please clean it up immediately with a paper towel and let your instructor know.
  • If glass breaks, do not pick it up with your bare hands. Notify your instructor immediately.
  • Be extra careful when handling the open flame and the boiling hot water in the can on the stove.
  • Please be sure to wear goggles for the pop can (I) and egg and a bottle (III) as the containers will be under pressure.
  • Wash your hands when you are finished with this and any other lab.

Procedures:

I. “Pop” Can
1. Set the wire mesh on the burner of the stove and turn the temperature to “high.”
2. Add a small amount of water to an empty soda can, to a depth of about 1 cm.
3. Place the can upright on the burner and heat it until the water boils and steam flows out of the top opening.
4. Using oven mitts, remove the steaming can from the hot plate with tongs.
5. Invert the soda can into an ice-water bath.

Record your results and observations:

II. Balloons in a Bottle

1. Place one small water balloon filled with air and one small water balloon filled with water in the bottle provided.
2. Cap with the gray rubber seal provided.
3. Weigh the bottle.
Mass in grams:

4. Use the white wine vacuum to apply a vacuum to the bottle.

Weight the bottle again. Record your results and observations, especially comparing the air-filled versus the water-filled balloon:

5. Remove the gray stopper.

Record your results and observations:

III. Egg and a Bottle
1. Obtain a bottle or flask and a boiled egg (shell removed).
2. Light a strip of paper on fire with matches and quickly drop into the jar/flask.
3. Place the boiled egg on top.

Record your observations:

IV. Pressure on a Pipette (from Flinn Scientific)

Edit: I have removed the instructions, as they were from Flinn. You can find them as a free .pdf here.

Edit: Here is video of how to do this technique.

Number of Books             Length of air column in mm
0
1
2
3
4
5

Graph your results.

balloons1

Balloons by Teodoro S Gruhl

V. Balloon Expansion and Contraction

1. Blow up a standard latex balloon.
2. Mark a line around the middle (approximate equator) using a ruler and sharpie pen. Measure the circumference of the balloon with the measuring tape  at the line.
Circumference of balloon at room temperature:

3. Place the balloon in the freezer for about 10 minutes. Pull it out and immediately measure the circumference again.

Circumference of cold balloon:

4. Heat the balloon with a hair dryer. Measure the circumference again.

Circumference of heated balloon:

As Mr. Anderson pointed out in the video in lesson 14, you could take the temperature of each balloon and use the information to calculate absolute zero. Cool! (I couldn’t help that)

VI. Hand Boiler

1. Obtain the hand boiler. Warm it with your hands.

Observations:

Conclusions:

Once you have completed the experiment and cleaned up, sit down and write a sentence or two to explain the results. It is always a good idea to do this part while the experiment is fresh in your mind.

Discussion:

Record any thoughts you have about the experiments, including:

  • Possible improvements to the procedures or how to tweak techniques
  • How the results differed from your expectations
  • Whether the goals were met
  • Suggestions for other experiments

Please leave a comment or send an e-mail if you have any questions before our meeting.

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