Before beginning, set up a data table similar to the Data Tables 3706

Before beginning, set up a data table similar to the Data Tables in the Lab Report Assistant section.
1. Select 5 or 6 large hard-bound books of roughly equal weight from a text book collection.
2. Optional: If a bathroom scale is available weigh each book and record the weights into the
data table.
3. Remove the end cap of the syringe spout and pull the piston approximately to the 60 mL
position.
4. Place the end cap onto the syringe spout and push down on the piston with your hand slowly
and steadily until the volume of the trapped gas is reduced to approximately 20 mL. Release
the piston and note whether it returns to the initial volume. Perform this test several times.
The position to which the piston returns each time will be your starting position. The gas
trapped in the syringe is at approximately the same pressure as the ambient surroundings.
5. Record this volume at Volume Trial 1 at 0 (zero books) into Data Table 1.
6. Place the base board of the Boyle’s Law apparatus on a flat, steady surface, such as a sturdy
table or the floor.
Figure 2: Syringe and base board
7. Place the syringe onto the base support board so that the syringe spout points downward.
NOTE : The base board has been drilled to accommodate the shape of the pointed end of the
syringe spout.
8. Place the other wooden board onto the top of the piston while supporting the apparatus with
one hand. Optionally have a partner hold the syringe and top board.

Experiment Boyle’s Law
Figure 3: Top and base boards in place with books stacked on top to produce pressure
9. Place one book onto the board above the piston and record the resulting gas volume at
Volume Trial 1 at 1 (one book) into Data Table 1. In order to read the volume of trapped gas,
always read the measurement on the side of the piston that is in contact with the gas.
10. Place a second book onto the first book, allow the books to settle on the piston, and record
the changed gas volume.
11. Continue adding books and recording the resulting volumes until all 5 or 6 books are resting
on the board. Remember to steady the books, especially when the apparatus is being read.
12. Remove all the books from the piston and reset the apparatus to the initial volume recorded
in Step 3.
13. Repeat Steps 7 – 10 two more times to complete the data for a total of three trials. Remember
to reset the apparatus as instructed in Step 3 between each trial.
Calculations, Graphing & Analysis
1. Find the average of each set of three volumes and record these averages into Data Table 1,
Average Volume column.
2. Calculate the inverse 1/Vavg (mL-1) of each average volume and record these values into Data
Table 1.
3. Using the graphing function of your spreadsheet prepare a graph of “Pressure (Number of
Books) Vs Volume (mL)” with “Pressure” on the y-axis and “Volume” on the x‑axis.
4. Prepare a second graph showing pressure (number of books or weight) on the y-axis vs. 1/
Volume on the x axis. Boyle’s Law states that gas Pressure x Volume = a constant (k); PV=k or
V=k/P. Therefore, volume varies inversely with pressure. Thus the graph of the gas pressure
values (Y axis) to values of the inverse of the volume (X axis) should show as a straight line
with a slope of ‘k’. Use the trend line function of the graphing software to have Excel put
the equation of the line directly on the graph (y = mx + b). “b” is the value where the line
intersects with the y-axis and roughly represents the atmospheric pressure in the units used
on the pressure axis − books, etc.

Experiment Boyle’s Law
NOTE : Remember that air pressure around us is 14.7 lbs/in2 − 101kPa, 760 mmHg or 1,035 g/
cm2 − at sea level (one atmospheric pressure) and the added mass from the plunger itself – while
negligible – will increase the pressure further. The slope line obtained for the second plot crosses
the y-axis of the graph above or below the origin, which tells us that there is pressure on the gas
even when there are no books on the piston.
IMPORTANT : Make certain to verify with your instructor whether they have any special
requirements for creating the graphs. Depending on your instructor’s requirements, the graphs
can be plotted in book units or converted to pressure units.
5. The local atmospheric pressure obtained through the above method must be added to all
pressure readings to obtain Total Pressure PT. Record Total Pressure PT into the data table
corresponding to each Pressure (Number of Books).
6. Finally, calculate the product of Ptotal x Vavg for each trial and record these values into Data
Table 1. NOTE: These values represent “k” and should be relatively close together.

**need these questions answered also.
1. Find the average of each set of three volumes and record these averages in the data table.
2. Calculate the inverse 1/Vavg (mL-1) of each volume and record these values in data table.

Experiment Boyle’s Law
3. Using the graphing function of your spreadsheet prepare a graph of “Pressure (Number of
Books) Vs Volume (mL)” with “Pressure” on the y-axis and “Volume” on the x‑axis.

Experiment Boyle’s Law
4. Prepare a second graph showing pressure (number of books or weight) on the y-axis vs. 1/
Volume on the x axis. (Boyle’s Law states that gas Pressure x Volume = a constant (k); PV=k or
V=k/P. Therefore, volume varies inversely with pressure. Thus a graph of the gas pressure (Y
axis) to the inverse of the volume (X axis) should be a straight line with a slope of ‘k’. Use the
trendline function of the graphing software to have Excel put the equation of the line directly on
the graph (y=mx+b). “b” is the value where the line intersects the y-axis and roughly represents
the atmospheric pressure in whatever units were used on the pressure axis (books, etc)

Experiment Boyle’s Law
NOTE : Remember that air pressure around us is 14.7 lbs/in2 (101kPa or 760 mmHg or 1,035 g/
cm2) at sea level (one atmospheric pressure) and the added mass to the plunger will increase
it further. The line obtained for the second plot crosses the y-axis of the graph above or below
the origin, which tells us that there is pressure on the gas even when there are no books on the
piston.
Depending on your instructor’s requirements the graphs can be plotted in book units or converted
to pressure units.
5. The local atmospheric pressure obtained through the above method must be added to all
pressure readings to obtain PT (Total Pressure)
6. Finally, calculate the product of Ptotal x Vavg for each trial and record these values in the data
table. These values represent “k” and should be relatively close together.

Boyles Law Worksheet-1.xls

0
0
0
0.000
0
0

0
0
0
0
0
0

0
0.000
0.000
0.000
0.000
0.000

0
0.00
0.00
0.00
0.00
0.00

56.66
56.66
53.66
51.66
48.66
46.66

Total Pressure
(pascals)

Total
Pressure *
vol

0.0176491
0.0176491
0.0186359
0.0193573
0.0205508
0.0214316

101,050
101,050
101,050
101,050
101,050
101,050

5,725,483.52
5,725,483.52
5,422,334.02
5,220,234.35
4,917,084.85
4,714,985.19

Local Barometric (in)
Local Barometric (mm)
Local Barometric (pascals)
Notes:

29.84
757.936
101,049.83

102,000

Boyles Law: Pressure vs Volume

100,000
98,000
96,000
94,000
92,000
90,000