The lab requirements are in documents lab1 and lab2.pdf files. The worksheet has questions that need to be answered. Thank you.
Experiment 2Using the Ideal Gas Law Experiment Inventory
Materials 10 mL Hydrogen Peroxide (H2O2)
Yeast Packet
Paper Clip
Rubber Band
*Clear Tape
*Internet Access
*100 mL Warm Tap Water
*500 mL Tap Water
Labware 10 mL Graduated Cylinder
100 mL Graduated Cylinder
250 mL Beaker
250 mL Erlenmeyer Flask
500 mL Beaker
24 in. Flexible Tubing
3 in. Rigid Tubing
2 Pipettes
Glass Stir Rod
Thermometer
Stopper with 1-hole
*Timer (stopwatch, clock, internet, etc.)
Note: You must provide the materials listed in *red.
EXPERIMENT 2: USING THE IDEAL GAS LAW
In this experiment, you will use a catalyst to observe a reaction that obeys the Ideal Gas Law.
PROCEDURE
1. Prepare the materials for the apparatus as shown in Figure 11. Insert the smaller rigid tubing into one end of the larger, flexible tubing. Insert the free end of the rigid tubing securely into the rubber stopper hole.
CAUTION: Be careful when working with rigid tubing. This tubing is made of glass and can break if excess force is applied.
2. Bend the free end of the flexible tubing into a U-shape, and use a rubber band to hold this shape in place. This will allow you to more easily insert the end of the flexible tubing into the inverted graduated cylinder. Make sure the tubing is not
Figure 11: Setup of the gas-collection apparatus.
pinched and that gas can flow freely through it.
3. Fill the 100 mL graduated cylinder with tap water to the 100 mL mark.
4. Fill the 500 mL beaker with 400 mL of tap water.
5. Using the thermometer, measure the temperature of the water in the 500 mL beaker and record it in Table 2 on the Experiment 2 Data Sheet.
6. Use the internet to determine the barometric pressure in the room, and record it in Table 2 on the Data Sheet.
Hint: If necessary, use the regional pressure as a close substitute to the room pressure; this can easily be found online. You may need to convert this value from inches of mercury (inHg) or bars (bar) to atmospheres (atm). For reference, 1 inHg = 0.033 atm and 1 bar = 0.987 atm.
7. Mix 100 mL of warm water (45 °C) and one packet of baker’s yeast in a 250 mL beaker. The warm water will activate the yeast from the dormant (dry) state. Be sure to mix the solution well with a glass stir rod until the yeast is completely dissolved.
Hint: The water must be between 42–47°C, otherwise, you will kill the yeast (i.e., no activation).
8. Use a 10 mL graduated cylinder and pipette to measure out 5 mL of hydrogen peroxide (H2O2). Pour the hydrogen peroxide into the Erlenmeyer flask, and securely place the stopper with the attached stopper tube into the top of the Erlenmeyer flask.
9. Clean the 10 mL graduated cylinder by rinsing it at least three times with tap water. Dispose of the rinse down the drain.
10. Cover the opening of the 100 mL graduated cylinder with two or three fingers and quickly turn it upside down into the 500 mL beaker already containing 400 mL of water. DO NOT remove your fingers from the opening until the graduated cylinder is fully submerged under the water. If the amount of trapped air exceeds 50 mL, refill the cylinder and try again. You want as little air as possible to be in the graduated cylinder.
11. Insert the U-shaped flexible tubing into the beaker, and carefully snake it into the submerged opening of the graduated cylinder.
12. Secure the graduated cylinder to the beaker by bending a paper clip around the graduated cylinder and using a piece of clear tape to hold it in place.
13. With the cylinder vertical, record the volume of air inside (the water line) in Table 2 on the Data Sheet.
14. Using a pipette, measure out 5 mL of yeast solution into the rinsed 10 mL graduated cylinder.
15. Remove the stopper (still connected to the hose) from the Erlenmeyer flask. Get your timer ready.
16. Quickly pour the 5 mL of yeast solution into the Erlenmeyer flask. Immediately place the stopper securely in the opening of the Erlenmeyer flask by gently twisting it down into the flask.
17. Start timing the reaction with the your timer as soon as you seal the flask with the stopper. If necessary (i.e., if you are using a clock or a watch), record the start time of the reaction in Table 3 on the Experiment 2 Data Sheet.
18. Carefully swirl the Erlenmeyer flask to mix the two solutions together. Bubbles should soon begin to form in the 100 mL graduated cylinder.
Hint: If gas bubbles are not immediately visible, make sure the stopper is on tight and the tubing is not leaking.
19. Continue to swirl the Erlenmeyer flask, and let the reaction run until no more bubbles form (to assure the reaction has gone to completion).
Hint: Catalase in the yeast works best around the temperature of the human body. You can speed up the reaction by warming the Erlenmeyer flask with your hands.
20. Record the time when the reaction finished, and then the total reaction time in Table 3 on the Data Sheet. Also record the final volume of air in Table 2. Remember to read the flask content at eye-level and measure from the bottom of the meniscus.
21. Take a photo of your complete lab set up. Remember to include your name and lab access code handwritten in the background of the photo. Pour all other liquids down the drain, and clean the labware.
Experiment 1 Charles’ Law Experiment Inventory
Materials 8 oz. Styrofoam® Cup
Graph Paper
*Ice
*Pencil
*Tap Water
Labware 10 mL Sealable Syringe with Cap
Thermometer
Ruler
*Timer (stopwatch, clock, internet, etc.)
Note: You must provide the materials listed in *red.
EXPERIMENT 1: CHARLES’ LAW
In this experiment, you will explore the relationship between temperature and volume, and connect this to Charles’ Law.
PROCEDURE
1. Fill the syringe halfway with air, and seal the syringe by screwing the cap on. Record the volume (mL) of gas in the cylinder in Table 1 on the Experiment 1 Data Sheet.
2. Using a timer, hold the top of the thermometer up in the air for 30 seconds. Record the temperature of the room in Table 1 on the Data Sheet.
3. Fill one Styrofoam® cup with hot tap water. Place the thermometer in the cup.
LAB SAFETY: Avoid using extremely hot water. Handle hot water carefully.
4. Fully submerge and hold the air-filled syringe in the hot water for 30 seconds. Use the timer to monitor time.
5. Gently push the piston down until the plunger cannot move any farther. Observe the new volume inside of the syringe. Record this volume and the water temperature in Table 1 on the Data Sheet.
6. Prepare a cup of water mixed with ice. Repeat Steps 4 and 5 for the cold water bath. Record the volume and temperature in Table 1 on the Data Sheet.
7. Convert all measured temperatures from degrees Celsius to Kelvin, and record your results in Table 1 on the Data Sheet. When you’re done, take a picture of your completed lab set up. Remember to include your name and lab access code handwritten in the background of the photo.