Gay-Lussac Law (Pressure vs
Temperature)
1.
Construct
a graph of pressure (y-axis) vs Celsius temperature (x-axis) using a computer
spreadsheet program, such as Microsoft® Excel.
Suggestions for using Excel:
a.
Open
a new blank workbook.
b.
Title
1st column with the name of your x-variable, such as “Celsius
Temperature” or “°C.”
c.
Enter
the observed Celsius temperatures as measured in class in this column. (There should be no blank rows between the
title and the data or within the data.)
d.
Title
2nd Column with the name of your y-variable, such as “Pressure,
lb/in2” or “Pressure, kPa.”
e.
Enter
observed pressures in the 2nd column, corresponding to the
temperatures.
f.
Select
the information to be charted by dragging the cursor through the data area
including titles, beginning at the upper left corner and ending at the lower
right corner.
g.
While
the data is still selected (if inadvertently unselected, redo step “f”), click
on Insert from the main menu and then Chart and select “XY
(Scatter).” Then, click on the
chart Sub Type that you prefer (the first option with points only, no
connecting lines, is recommended).
h.
Click
on Next and Next again for the next two dialog
(option) boxes.
i.
Enter
a chart title of your preference that includes your name and descriptive
titles for the x (temperature) and y (pressure) values. You may also make changes to the gridlines
on the chart at this time.
j.
Click
the Next button.
k.
Select
As new sheet option for chart location and then Finish.
l.
Position
the cursor on one of the data points and then right click and select Add Trendline.
m.
Select
Linear and then Options and input approximately “320” in the
Forecast Backward box, followed by OK.
You may modify chart parameters by right-clicking on the desired area of the
chart at any time. To print the chart,
go to File Print on the main menu or click on the Printer icon.
2.
From
your graph, determine the temperature at which the pressure appears as if it
would become zero and indicate this temperature on your chart. Theoretically, this should be the absolute
zero of temperature (-273.15 °C). Also
indicate this theoretical value on your chart.
3.
Convert
your observed temperatures to Kelvins and calculate P/T (Kelvins) for each of
the measurements. Theoretically, this
ratio should be constant from measurement to measurement. How close does your data come to constancy
in significant figures, 0, 1, 2, 3, etc?
4.
Submit
your results from #3 and the graph, along with Experiment 13.A.1, using the
modified data obtained in class. Answer
Experiment 13 questions Q.4, Q.5, Q.6, Q.7, Q.9, Q.10, Q.11, and Q.12.