Gas Laws Experiments Name: ______________________________Page 1 of 12
ASK ME WHICH OF THESE YOU ARE TO DO.
Boyle’s Law-Gas Pressure and Volume (You should have two graphs and data
tables and the answers to the questions at the end of this lab.)
On the desktop is an icon for ―Logger Pro 3.##‖. Open this program. Go to file open folder Chemistry with
Vernier. Choose 06 Boyle’s law and open it.
In this simple experiment, you will use a computer-interfaced Gas Pressure Sensor and a gas syringe to study
the relationship between gas pressure and volume. Temperature and amount of gas will be kept constant. The
results will be expressed in words, in a table, with a graph, and with a mathematical equation. These are four
methods commonly used by scientists to communicate information.
This experiment is similar to one first done by Robert Boyle in 1662—without the use of a computer, of
course. The relationship you will discover is known as Boyle’s law.
OBJECTIVES
In this experiment, you will
• Use a Gas Pressure Sensor and a gas syringe to measure the pressure of an air sample at several
different volumes.
• Make a table of the results.
• Graph the results.
• Predict the pressure at other volumes.
• Describe the relationship between gas pressure and volume with words and with a mathematical
equation.
MATERIALS
computer
Vernier computer interface
Logger Pro
Vernier Gas Pressure Sensor with 20 mL gas syringe
Figure 1
PROCEDURE
1. Prepare the Gas Pressure Sensor and an air sample for data collection.
a. Plug the Gas Pressure Sensor into Channel 1 of the computer interface.
b. With the 20 mL syringe disconnected from the Gas Pressure Sensor, move the piston of the syringe
until the front edge of the inside black ring is positioned at the 10.0 mL mark.
c. Attach the 20 mL syringe to the valve of the Gas Pressure Sensor.
2. Prepare the computer for data collection by opening the file ―06 Boyle’s Law‖ from the Chemistry with
Computers folder.
3. Click to begin data collection.
4. Collect the pressure vs. volume data. It is best for one person to take care of the gas syringe and for
another to operate the computer.
Gas Laws Experiments Name: ______________________________Page 2 of 12
a. Move the piston to position the front edge of the inside black ring (see Figure 2) at the
5.0 mL line on the syringe. Hold the piston firmly in this position until the pressure value stabilizes.
Figure 2
b. When the pressure reading has stabilized, click . Type ―5.0‖ in the edit box. Press the ENTER
key to keep this data pair. Note: You can choose to redo a point by pressing the ESC key (after
clicking , but before entering a value).
c. Continue the procedure for volumes of 7.5, 10.0, 12.5, 15.0, 17.5, and 20.0 mL.
d. Click when you have finished collecting data.
5. In your data table, record the pressure and volume data pairs displayed in the table (print a copy of the
table and graph).
6. Examine the graph of pressure vs. volume. Based on this graph, decide what kind of mathematical
relationship you think exists between these two variables, direct or inverse. To see if you made the right
choice:
a. Click the Curve Fit button, .
b. Choose Variable Power from the list at the lower left. Enter the power in the Power edit box that
represents the relationship shown in the graph (e.g., type ―1‖ if direct, ―–1‖ if inverse). Click .
c. A best-fit curve will be displayed on the graph. If you made the correct choice, the curve should match
up well with the points. If the curve does not match up well, try a different exponent and click
again. When the curve has a good fit with the data points, then click .
7. Once you have confirmed that the graph represents either a direct or inverse relationship, print a copy of
the graph, with the graph of pressure vs. volume and its best-fit curve displayed. Enter your name(s) and
the number of copies you want to print.
8. To confirm that an inverse relationship exists between pressure and volume, a graph of pressure versus
the reciprocal of volume (1/volume or volume-1) may also be plotted. To do this using Logger Pro, it is
necessary to create a new column of data, reciprocal of volume, based on your original volume data.
a. Choose New Calculated Column from the Data menu.
b. Enter ―1/Volume.‖ as the Name, ―1/V‖ as the Short Name, and ―1/mL‖ as the Unit.
c. Enter the correct formula for the column, (1/volume) into the Equation edit box. Type in ―1‖ and ―/‖.
Then select ―Volume‖ from the Variables list. In the Equation edit box, you should now see
displayed: 1/―Volume‖. Click Done.
d. Click on the horizontal-axis label, select ―1/Volume‖ to be displayed, and click .
9. Make a best-fit curve.
a. Click the Curve Fit button, .
b. Choose Variable Power from the list at the lower left. Type ―1‖ in the power edit box. Click .
c. Click .
If the relationship between P and V is an inverse relationship, the plot of P vs. 1/V should be direct; that
is, the curve should be linear and pass through (or near) your data points. Examine your graph to see if
this is true for your data.
Print the graph of P vs. 1/V.
Gas Laws Experiments Name: ______________________________Page 3 of 12
Print screen of the graph and data. Paste the graphic to the bottom of the next page.
DATA (This Should Be On Your Print Out.)
Volume 5.0 7.5 10.0 12.5 15.0 17.5 20.0
(mL)
Pressure ______ ______ ______ ______ ______ ______ ___ __
(kPa)
Look at general trends. When looking for general trends, mentally round off the numbers above to two
significant figures.
PROCESSING THE DATA (Type Your Answers Here)
1. See the data table and note the pressure when the volume is 10.0 mL, and when the volume is 5.0 mL.
What happened to pressure when the volume was halved?
2. See the data table and note the pressure when the volume is 20.0 mL. Compare this pressure to the
pressure when the volume is 10.0 mL. What happened to the pressure when the volume was doubled?
3. From your graph, what is the pressure when the volume is 16 mL? 8 mL? How do these values compare?
4. What would the pressure be at 40.0 mL? At 2.5 mL? Explain how you determined these values.
5. What is the relationship between gas pressure and volume (Boyle’s law) in words?
6. Do gas pressure and volume vary directly or inversely? Explain.
7. Write an equation to express the relationship between gas pressure and volume. Use the symbols P, V,
and k. (Formula for a straight line (y = mx + b) watch the units. Use your linear graph from above.)
Gas Laws Experiments Name: ______________________________Page 4 of 12
Gay-Luccac’s Gas Temperature and Pressure
On the desktop is an icon for ―Logger Pro 3.##‖. Open this program. Go to file open folder Chemistry with
Vernier. Choose 07 Gas Temperature and Pressure and open it.
Gases are made up of tiny particles. The particles are in constant motion and exert pressure when they strike
the walls of their container. In this simple experiment, you will use a computer-interfaced pressure sensor
and an air sample in a stoppered flask to study the relationship between gas pressure and temperature. The
volume and amount of gas will be kept constant. The results will be expressed in words, in a table, with a
graph, and with a mathematical equation.
OBJECTIVES
In this experiment, you will
• Use a computer-interfaced pressure sensor to measure the pressure of an air sample at several different
temperatures.
• Measure temperature.
• Make a table of the results.
• Graph the results.
• Predict the pressure at other temperatures.
• Describe the relationship between gas pressure and temperature with words and with a mathematical
equation.
MATERIALS
computer heavy-wall plastic tubing
Vernier computer interface 125 mL flask
Logger Pro four 1 liter beakers Use the coffee can
in the red box under the shelves.
Vernier Gas Pressure Sensor ice
Vernier Temperature Probe hot plate
rubber stopper assembly glove or cloth
ring stand and utility clamp
Figure 1
Gas Laws Experiments Name: ______________________________Page 5 of 12
PROCEDURE
1. Obtain and wear goggles.
2. Prepare a boiling-water bath. Put about 800 mL of hot tap water into large coffee can and place it on a
hot plate. Turn the hot plate to a high setting.
3. Prepare an ice-water bath. Put about 700 mL of cold tap water into a second plastic shoe box and add ice.
4. Put about 800 mL of room-temperature water into another plastic shoe box.
5. Put about 800 mL of hot tap water into a third plastic shoe box.
6. Prepare the Temperature Probe and Gas Pressure Sensor for data collection.
a. Plug the Gas Pressure Sensor into Channel 1 of the computer interface.
b. Plug the Temperature Probe into Channel 2 of the computer interface
c. Obtain a rubber-stopper assembly with a piece of heavy-wall plastic tubing connected to one of its two
valves. Attach the connector at the free end of the plastic tubing to the open stem of the Gas Pressure
Sensor with a clockwise turn. Leave its two-way valve on the rubber
stopper open (lined up with the valve stem as shown in Figure 2) until
Step 6f.
d. Insert the rubber-stopper assembly into a 125 mL Erlenmeyer flask.
Important: Twist the stopper into the neck of the flask to ensure a tight
fit. Figure 2
Figure 3
e. Close the 2-way valve above the rubber stopper—do this by turning the valve handle so it is
perpendicular with the valve stem itself (as shown in Figure 3). The air sample to be studied is now
confined in the flask.
7. Prepare the computer for data collection by opening the file ―31 Pressure and Temp‖ from the Physical
Science w Computers folder.
8. Click to begin data collection.
9. Collect pressure vs. temperature data for your gas sample:
a. Place the flask into the ice-water bath. Make sure the entire flask is covered (see Figure 3). Stir.
b. Place the Temperature Probe into the ice-water bath.
c. When the pressure and temperature readings displayed in the meter stabilize, click . You have
now saved the first pressure-temperature data pair.
10. Repeat the Step-9 procedure using the room-temperature bath.
11. Repeat the Step-9 procedure using the hot-water bath.
12. Use a ring stand and utility clamp to suspend the Temperature Probe in the boiling-water bath. To keep
from burning your hand, hold the tubing of the flask using a glove or a cloth. After the Temperature
Probe has been in the boiling water for a few seconds, place the flask into the boiling-water bath and
repeat the Step-9 procedure. Remove the flask and the Temperature Probe after you have clicked .
CAUTION: Do not burn yourself or the probe wires with the hot plate.
13. Click when you have finished collecting data. Turn off the hot plate. Record the pressure and
temperature values in your data table, or, if directed by your instructor, print a copy of the table.
14. Examine your graph of pressure vs. temperature (°C). In order to determine if the relationship between
Gas Laws Experiments Name: ______________________________Page 6 of 12
pressure and temperature is direct or inverse, you must use an absolute temperature scale; that is, a
temperature scale whose 0° point corresponds to absolute zero. We will use the Kelvin absolute
temperature scale. Click on the horizontal-axis label, select ―Temp Kelvin‖ to be displayed on the
horizontal axis. Autoscale both axes starting with zero, double-click in the center of the graph to view
Graph Options, click the Axes Options tab, and select Autoscale from 0 for both axes.
15. Decide if your graph of pressure vs. temperature (K) represents a direct or inverse relationship:
a. Click the Curve Fit button, .
b. Choose your mathematical relationship from the list at the lower left. If you think the relationship is
linear (or direct), use Linear. If you think the relationship represents a power, use Power. Click
.
c. A best-fit curve will be displayed on the graph. Click . If you made the correct choice, the
curve should match up well with the points. If the curve does not match up well, try a different
mathematical function and click again. When the curve has a good fit with the data points,
then click .
16.Print a copy of the graph of pressure vs. temperature (K). The curve fit should still be displayed on the
graph. Enter your name(s) and the number of copies you want to print.
17.Use your best-fit curve and the power of Logger Pro to obtain answers to Question 3.
a. Choose Interpolate on the Analyze menu.
b. Move the cursor along the graph to a position above 350 K—the temperature displayed on the screen
should be 350. The pressure displayed on the screen is your pressure value for 350K. Record it.
c. Move the cursor along the graph until the temperature is 200 K. Read and record pressure for 200 K.
18.Change the right tickmark on the x-axis to 450 before repeating the procedure for 400K.
Gas Laws Experiments Name: ______________________________Page 7 of 12
DATA
Water bath Temperature Temperature Pressure
(°C) (K) (kPa)
Ice ______ ______ ______
Room temperature ______ ______ ______
Hot ______ ______ ______
Boiling ______ ______ ______
PROCESSING THE DATA (Send A Printout Of The Data And Graph With The Answers To These Questions)
1. What is the relationship between gas pressure (P) and temperature (T) in words?
2. Explain this relationship using the idea of particle speed.
3. Write an equation to express the relationship between pressure and temperature. Use the symbols P, T,
and k. (Formula for a straight line (y = mx + b) watch the units. Use your linear graph from above.)
4. Should the graph go through the origin (0,0)? Explain. (If ―b‖ in y = mx +b is less than 5% of the largest
―y‖ value consider it to be zero’)
5. Explain how you got your answer so show your work. Use your straight line formula from #3
(y = mx + b) Show work.
According to your graph, what would the pressure be at 350 K (77°C)?
At 200 K (–73°C)?
At 400 K (127°C)?
6. What is the temperature when the pressure is zero?
Gas Laws Experiments Name: ______________________________Page 8 of 12
Charles' Law
(Do your Excel file. Answer any questions on that file)
Description
This procedure uses the air trapped inside of a Beral pipette at different temperatures to demonstrate Charles'
Law. In order to do this, we must assume that a constant pressure is exerted by equal depths of hot and cold
water and that that pressure causes no significant distortion of a Beral pipette.
Materials
Beral pipette with constricted tip (These will have to be pulled to get a constricted tip)
250mL beaker
hot plate
thermometer
large container
ice
tap water
Introduction
This procedure uses the air trapped inside of a Beral pipette at different temperatures to demonstrate Charles'
Law. In order to do this, we must assume that a constant pressure is exerted by equal depths of hot and cold
water and that that pressure causes no significant distortion of a Beral pipette.
Procedure
1. Tape a dry, pulled, Beral pipette to the end of metal tongs. Tape it loosely so the pipet isn’t squeezed.
2. While the water heats, completely fill the pipette and count how many drops are contained in the full
pipette Total Volume (Total drops).
3. For the first value, take the room temperature pipet and put it into the ice water. Carefully count the
drops of water that enter into the pipet after holding the pipet in the cold water for at least 1 minute..
4. Lower this assembly into a 250 mL (or larger) beaker of hot water (temperature should NOT be in
excess of 75 °C as this can cause some distortion of the pipette bulb). When the water in the beaker
approaches 75 °C, remove the beaker from the hot plate using beaker tongs.
5. Allow the pipet to remain under water until bubbles cease to emerge from the tip. Read and record
the temperature of the hot water bath (Th).
6. Remove the pipette from the hot water bath and instantly place it into ice water. Allow sufficient time
(at least one minute) for it to cool and for water to enter the pipette. Read and record the temperature
of the cold water bath (Tc).
7. Remove the pipette from the water and carefully count drops of water which have entered the pipette
during cooling (Cold drops).
8. Remove the beaker of water from the hot plate. Repeat the experiment at lower temperatures for the
hot water bath. You MUST have 7 measured values. I would like for you to have 10 values for your
graph.
For data table: Column 1 – Celsius Temperature(h), Column 2 – Volume change (Counted drops), Column 3 –
Total Volume (Total volume + volume change).
Graph: Total Volume vs. Celsius Temperature
Calculate the Percent Error for your experiment. Take your slope formula from the graph,
calculate the temperature at which the volume will be zero. Compare this answer to the correct
answer of -273 oC in your % error formula. Write a conclusion paragraph about your results and
the scientific principles addressed by this experiment.
Safety: Hot plates and hot water can cause burns. Handle hot materials with caution.
Gas Laws Experiments Name: ______________________________Page 9 of 12
Graph Instruction for Excel
1. Open Excel
2. In A1 type your name. In Student does not turn in homework. In C1 type your lab partner’s name.
3. In A2 put your title
4. In A3 type ―Purpose: then your purpose.‖
5. In A4 Type ―Data:‖
6. In A5 Type ―Temperature (T2)‖ In B5 type the value of your cold temperature.
7. In A6 Type ―Total Drops (V1)‖ In B6 type the value of your total drops.
8. In A7 Type ―Temperature (degrees C)‖
9. In B7 type ―Δ Volume‖
10. In B8 - type your measure # of drops change for each temperature. (This comes from your raw data)
11. In C7 type ―Total volume after heating.‖
12. In C8 – Type ―=‖ put in the value from B6 ―+‖ then click on cell B8.
13. Press enter then arrow back to cell B8. Move your cursor over the small square at the
bottom right of B8. When the cursor changes to the small + you see here.
14. Highlight B8 - ??(measured values) and C8-?? Then click this button
15. Choose XY scatter. Note: The title
16. Complete the graph with a title, label the X and Y axis. And finish should be Y vs. X
17. Click on the Series box and press delete.
18. With the graph selected, click Chart/Add Trendline
19. The default is linear. Click the Options tab Check Display equation on Chart. Click OK
20. When the equation shows Copy ―Total Volume‖ from C7 then move
your cursor beside the ―y‖ delete the letter ―y‖ and paste. Then type ―T‖ in Place of ―x‖. Type the units
for the slope as seen below. Highlight all the text in the box and change the size of the font to 12 point.
Your final formula should look like this
Total Volume = (0.8639 drop/oC) T + 196.11 drops
21. In A? (a cell below your graph) type ―Conclusion:‖ in the next A cell type your conclusion. Make sure
that the graph is NOT selected.
You can change font size, bold, center text and more to make the print out pretty.
Gas Laws Experiments Name: ______________________________Page 10 of 12
Molecular Mass Determination of Butane (C4H10)
Formal Lab Report
Purpose: To determine the molar mass of butane (C4H10)
Equipment: Erlenmeyer Flask Water basin
Piece of glass Butane lighter Graduated cylinder
Procedure:
1. Make sure the butane lighter is dry, and find its mass.
2. Fill the water basin with water.
3. Completely fill the flask with water.
4. Turn the flask upside down in the water basin, making sure there are no air bubbles
are inside.
5. Bubble the gas into the flask, until only 2 or 3 cm of water remains.
6. Put the piece of glass over the top of the flask and turn it over.
7. Using the graduated cylinder, measure the amount of water needed to completely
refill the flask. This is how much gas was collected.
8. Completely dry the lighter and find its mass.
9. Clean and dry the equipment and lab station.
10. Find the room temperature and barometric pressure.
11. Write a lab report: data table, calculations (molar mass and % error), conclusion.
Use your own paper. Ignore the questions although they may help you figure out
want to do with the calculations portion of your lab report.
Questions and calculations: (In the conclusion answer these questions. Write the
question)
1. How much butane did it take to fill the flask (mass)?
2. What was the volume of the gas in mL?
3. How many liters of gas is this?
4. How many moles of gas is this?
5. What is the density of the butane in g/L
molar mass
6. What is the molar mass of butane? (Use this formula – Density )
22.4 L
7. The formula for butane is C4H10. What is the mass of 1.00 mole of C4H10?
Gas Laws Experiments Name: ______________________________Page 11 of 12
Hydrogen and Oxygen Generating, Collecting, & Testing
Hydrogen is a clear, colorless gas which is said to be ―combustible,‖ meaning that it can burn quite readily.
Oxygen is also a clear, colorless gas that is said to ―support combustion,‖ meaning that it must be present for
combustible materials to burn. In this lab, you will be generating, collecting, and testing hydrogen and
oxygen gas. Hydrochloric acid is reacted with zinc to generate the hydrogen. (In general, any strong acid and
almost any metal reacts to produce hydrogen.) Hydrogen peroxide is added to manganese metal to generate
the oxygen. (Hydrogen peroxide decomposes by itself to produce water and oxygen at a slow, imperceptible
rate; the manganese oxide ―rust‖ which coats the manganese metal acts as a catalyst to speed up this
reaction.) By collecting and pop-testing (igniting) different hydrogen/oxygen mixtures, you will audibly
compare them to determine the most reactive (loudest) mixture.
Because this lab is performed on the microscale level, the explosions, though potentially loud, are
completely safe. On the other hand, the two solutions used in this lab, hydrochloric acid (HCl) and hydrogen
peroxide (H2O2), can cause serious damage should they come in contact with your eyes.
Materials
250 mL beaker (1) 10 mL graduated cylinder (1)
small test tube labeled ―H2 generator,‖ 1/6 full of Candle
zinc (1) Lighter from me
small test tube labeled ―O2 generator,‖ 1/6 full of 1 M hydrochloric acid (HCl)
manganese (1) 3% hydrogen peroxide (H2O2)
1-hole rubber stoppers with 1" nozzles (nozzles Permanent marker (1)
are cut from the tips of graduated pipets) (2) tap water
cut-off graduated pipet or super jumbo pipet (1)
Procedure:
Caution: Put on your goggles and apron now!!
Record all observations
1. Fill the beaker 3/4 full with tap water. This will act as a test tube holder, a temperature
regulator, and a water reserve during the experiment.
2. Using the graduated cylinder and the pen, mark the cut-off jumbo pipet to show six equal-
volume increments. This cut-off pipet will be referred to as the ―collection bulb‖ (see figure
below).
3. Light a candle.
4. The test tube labeled ―H2 generator‖ contains several pieces of zinc metal and is topped with a
1-hole stopper (with nozzle). Remove the stopper. Using the full length graduated pipet, add
enough 1 M HCl to fill the test tube to within 2 cm of the top. Replace the stopper and set the
generator in the beaker of water. Wait 5 seconds before beginning the next step.
5. Fill the collection bulb completely full of water. Place the end of the pipet over the end of the
generator and collect the hydrogen gas.
6. Once the collection bulb is filled with gas, hold it horizontally with its mouth roughly 1 cm
from the mid-section of the flame. Avoid putting the bulb directly in the flame. It will melt
and possibly burn. Should this happen, quench the tip in the beaker of water and obtain a new
bulb from the instructor. Gently squeeze a very small portion of the contents of the bulb into
the flame and observe. Repeat.
7. Repeat steps #4 through #6, generating, collecting, and testing oxygen this time. There are two important
differences to keep in mind. First, the test tube labeled ―O2 generator‖ does not contain zinc; it contains
pieces of manganese metal (with an oxide coating, MnO2). Second, hydrogen peroxide (H2O2), not HCl,
will be added to the test tube.
8. While generating both gases side by side, collect and test all different possible ratios of hydrogen and
oxygen. Be as consistent as possible each time. If either of the two reactions should slow down too much,
simply remove the stopper, carefully decant (pour off) the remaining liquid into the sink, and replace it
Gas Laws Experiments Name: ______________________________Page 12 of 12
with some fresh solution from the appropriate stock bottle. Replace the stopper; wait 5 seconds and
resume collecting the gas.
9. Create a bar graph that shows, in a logical fashion, the relative loudness of each of the samples that you
tested (including the pure hydrogen and oxygen). 15 pts
10. Collect the optimum mixture one more time. Instead of pop-testing it with the flame, take it to the
―rocket launch pad‖ and have the instructor supply the activation energy with a Tesla coil. Can you think
of ways to make your rocket go farther? Try them! What ratio of hydrogen, oxygen, and water produces
the greatest distance when the rocket is launched?
11. Dispose of the liquid down the drain. Try to reserve the solids for the next person.
Questions (No Formal Lab Report): 3 ½ pts each
1. Write a balanced equation for the reaction taking place inside the hydrogen generator.
2. Write a balanced equation for the reaction taking place inside the oxygen generator.
3. Define and explain the roll of catalysts.
4. Which do you think will have to be replaced first: the zinc in the hydrogen generator or the manganese in
the oxygen generator? Explain.
5. There are two reasons for filling the generators up so full. What are they ?
6. Explain your observations for the pop-test of pure hydrogen.
7. Explain your observations for the pop-test of pure oxygen.
8. Did you find any mixtures that produced no reaction at all? Explain how that could happen.
9. What proportion of hydrogen and oxygen produced the most explosive mixture? Why was that mixture
most explosive? (Think about volume to volume ration.)
10. Write a balanced equation for the reaction of hydrogen and oxygen.
11. Why don’t the hydrogen and oxygen in the collection bulb react as soon as they mix? What role does the
flame play?
12. If a small spark is needed to supply the activation energy for a small bulb of hydrogen-oxygen mixture,
how could the same small spark also act to supply the activation energy for an entire room-full of the
mixture? In other words, why does one not have to use a proportionately larger amount of energy to
spark a proportionately larger volume of hydrogen and oxygen? (Discuss Activation Energy)