_____University of Puget Sound
Experiment 3
Department of Chemistry
Chem 110
SPREADSHEETS AND DATA ACQUISITION PROGRAMS IN
CHEMISTRY
LABORATORY OBJECTIVES AND ASSESSMENTS
1. Develop spreadsheet and graphing skills.
a. Demonstrate proper entry of formulas using scientific notation.
b. Perform fill-down and fill-across operations.
c. Generate and format cells of various formats (decimal, scientific
notation, etc.).
d. Produce properly annotated and formatted x-y scatter plots.
2. Develop computer-based collection and analysis skills.
a. Collect paired experimental results (e.g., pressure and volume).
b. Identify graphical depictions of linear, variable power, or inverse
functions, and perform appropriate regression analyses.
c. Extract algebraic parameters (e.g., slope) from regression analysis.
3. Develop formal writing skills.
a. Export properly formatted tables and figures into a word processing
program.
b. Use appropriately voiced and tensed prose, in combination with tables
and figures, to make a Results Section.
INTRODUCTION
USING SPREADSHEETS FOR PREPARING TABLES AND FIGURES
One major objective of this exercise is to use spreadsheets for preparing tables and
figures for your laboratory reports. Another objective is to collect and plot experiment
results using a data collection interface. You will write two separate “Results” sections
of a formal report from the data you collected in Exercise 1 and Exercise 2 from this
experiment. This formal report writing exercise is due next week upon arrival at the
lab.
The formatting of the data tables you constructed in your lab notebook to collect
data in the lab does not always reflect the correct formatting for presenting the data
for a formal presentation. Once the data and/or plot are copied into the Word™
document the table can also be formatted using the Tables menu in Word™ and title
and captions can be added to the tables and figures.
DIFFERENCES BETWEEN SPREADSHEETS AND LAB DATA ACQUISITION PROGRAMS
Spreadsheet and plotting programs on personal computers were originally
developed for business use and, along with word processing programs, are
responsible for much of the tremendous growth of computer use in our society.
Modern spreadsheet programs contain most of the mathematical functions needed
by scientists. A spreadsheet represents an extremely fast and efficient method for
inputting data for both numerical calculations and graphical presentations of the
results. Some goals of this lab are to introduce you to some of the most commonly
used spreadsheet skills: entering data, doing simple calculations, plotting data,
formatting results for formal lab reports, and saving data onto the desktop. Other
goals of the experiment involve data collection and processing using laboratory
interfaces, data acquisition programs and associated applications.
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Some of the worksheets and charts developed in this write-up have been produced
with Microsoft Excel®, but any spreadsheet software can be used in conjunction with
these instructions with some modifications specific to each program.
A data collecting and plotting program used in laboratory procedures, LoggerPro,
will also be used to produce plots directly from data collected in the laboratory. This
application in conjunction with the appropriate interfaces will be used throughout the
semester.
The primary difference between a spreadsheet and a lab data-collecting program is
the input of data. A spreadsheet is designed for any kind of data, that is, text,
numerical, date or logical, as defined and input by a user. In contrast, a lab data
collection program is designed to receive analog electrical signals, either amperage or
voltage, directly from a detector. These data are converted to digital format and
stored directly into a memory array, often in a secure form that preserves the integrity
of the data and does not allow alteration by a user. As most modern labs use
instrumentation for separation, analysis or characterization of chemical species, these
programs are designed specifically for the type of data monitored as well as the
operation of the instrument, and also for the enormous quantity of data generated.
For example, a microsecond of FT-NMR data may generate several megabytes of raw
numbers, far too much for most spreadsheets. However, these raw data can then be
reduced to fairly concise results which can be summarized and tabulated for
publication using a spreadsheet and a word processor.
PROCEDURE
WORK IN PAIRS
EXERCISE 1
Temperature conversions from Celsius to Fahrenheit
With a new worksheet on the monitor of your computer and Microsoft® Excel or a similar
spreadsheet program operating, you should produce an exact copy of Figure 1, which is our first
example. The spreadsheet will convert the temperatures input to the Celsius column into
temperatures in Fahrenheit based on the relationship between the temperature scales:
T(°F)= 1.8 x T(°C) + 32
(1)
The spreadsheet on the left represents what you see in normal view and the one on the right shows
the formulas. Most of the entries in this worksheet must be made by using the Fill Down command
under Edit on the menu bar. The four cells that you need to fill from the keyboard are highlighted by
bold type. The remaining cells are filled from the typed ones in
This example illustrates the ease with which a formula in a cell may be filled by the Fill Down or Fill
Right command under Edit. The set of operations illustrated by this example are representative of a
process for copying and creating relative cell references, with the software intuitively changing the
cell reference as you fill down or to the right. For a simple progression such as this one it is also
possible to specify a series fill by step size to an end number.
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Figure 1. Examples of Worksheets 1 and 1ƒ. Converting Celsius to Fahrenheit from Excel.
You can view the formula that you have placed in a given cell by observing the formula bar at the top of the
worksheet. This requires that you highlight the cells one at a time by using either the mouse or the
directional arrows. During the development of a worksheet, you may want to simultaneously observe the
formulas in all of the cells. This can be accomplished by altering the view of the worksheet so that only the
formulas and not the contents of the cells are shown. This view can be accessed via the keystroke;
“command-` ” or via the Preferences (command-,) and checking the Formulas box under the View option.
In many cases the contents in a cell will not be visible because the width of the cell is too narrow. The cell
width can be increased (or decreased) by clicking the letter of the column, then double-clicking (control+
click) on the border. This sets the width to the widest entry in the column.
The worksheet has done the calculations for you, but it is not in the format desired for a table to be pasted
into a Word document and a Figure caption can be added. Clicking on the row number (or column letter)
selects the entire row (column). Select row 1. From the top menu, select Insert>row. Now you can type a
title for the table.
To format a cell or block of cells, first select it and then click Format > cells. A dialog box appears with tabs
for number, alignment, font, border, patterns and protection. You will usually only format the number,
alignment and border. Alternatively, under View you can display the formatting toolbox. You should
produce the table in a Word document exactly as it appears below:
Table 1. Conversion of Celsius to Fahrenheit
Celsius (°C)
Fahrenheit (°F)
0
32
10
50
20
68
30
86
40
104
50
122
60
140
70
158
80
176
90
194
100
212
110
230
120
248
The format of this table is consistent with the instructions in the IV. Guidelines For Making Tables
handed out in lecture, namely
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• Three and only three horizontal lines
• Title, beginning with table number
• Values centered under the heading with the units in the heading.
If you need assistance in producing these results, be sure to ask your professor or CA.
Graphical Presentations
The presentation of this information in graphical format (a chart) may be quickly achieved by simple
operations using Chart under Insert. The first step is to choose the type; you will ALWAYS use
“XY(scatter)” with NO connecting lines. When you click “Next” a preview will appear. Click the
series tab, and then use the icons to select the x data and the y data and name the figure as “Figure 2.
The relation between Celsius and Fahrenheit.” Title the axes. Use the remaining tabs to remove
gridlines and legend. When you select “Finish” the graph appears on the worksheet; immediately
click the Plot area and set fill to “No Fill”, and click the chart area and select “No Fill” and borders to
“None”. Finally, right click a data point and select “add Trendline”. You should reproduce figure 2
below exactly.
Figure 2. Plot from Table 1. Conversion of Celsius to Fahrenheit illustrating the
proper formatting (no title, background, legend or grid lines.)
If you need assistance in producing these results, be sure to ask your professor or CA.
The graph should now be complete with a caption for the chart, the “x” axis labeled and showing
units, and the “y” axis labeled and showing units. Later, you may want to explore the various options
for graphical presentations under Chart on the tool bar ribbon. Sketch this plot in your lab
notebook.
With the worksheet as the current window, enter in cell A2 the numeric value -50. You should
observe that the chart now represents the new values that have been calculated by the worksheet for
an initial value of -50° C. If you activate the worksheet by clicking on cell A2, you will be able to
change this value in this cell at will and observe the corresponding changes in the graphical
presentation. It is possible to reduce the horizontal size of the worksheet by moving the borders and
thereby gaining space so that the chart may be increased in size in the horizontal direction. Sketch
this plot in your lab notebook.
NAMING AND SAVING FILES
Record this file name in your lab notebook with a short description of what the file represents and the
location (Flash Drive). A couple of statements and/or a sketch of the figure are suggested.
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To SAVE this data simply select the SAVE command from the FILE menu. After the dialog box
appears click on the button designated DESKTOP. Give your spreadsheet file a name using the
following format:
Lastname_Exp#_E1.xls
(Your last name underscore experiment number underscore exercise (or part) number dot xls)
Note: Use this naming format for all files saved on Chemistry Lab Computers.
Click the SAVE button. You can transfer your document to a flash drive after quitting from the
program or email the files to your personal mailbox.
E.1
From the Excel worksheet, copy the spreadsheet and the chart embedded on the
same page with the chart below the spreadsheet. Paste these into a new page in
Microsoft Word (or the word processor you use), save and preview a copy of your
spreadsheet and the chart embedded on a single page. Show this preview to your CA
and save a copy of both the Excel™ document as well as the Word™ document to your
flash drive before moving on to the next exercise.
This data will become the basis for a Results Section for Exercise 1. See
the What–to-Do Section at end this handout. Read Laboratory Guideline
Section VII. GUIDELINES FOR WRITING THE RESULTS AND
DISCUSSION SECTIONS OF A REPORT.
EXERCISE 2
Pressure-Volume Relationship in Gases
The primary objectives of this exercise are to collect data showing the relationship
between the pressure and volume of a confined gas and then analyze the data using
graphs. The gas we use will be air, and it will be confined in a syringe connected to a
Pressure Sensor (see Figure 3). When the volume of the syringe is changed by moving
the piston, a change occurs in the pressure exerted by the confined gas. This pressure
change will be monitored using a Pressure Sensor. It is assumed that temperature will
be constant throughout the experiment. Pressure and volume data pairs will be
collected during this experiment and then analyzed. From the data and graph, you
should be able to determine what kind of mathematical relationship exists between
the pressure and volume of the confined gas. Historically, this relationship was first
established by Robert Boyle in 1662 and has since been known as Boyle's law.
Figure 3. Syringe and pressure sensor set-up. The arrow indicates the front (or bottom) edge
of the black ring on the syringe piston.
PROCEDURE
EXERCISE 2A
DATA COLLECTION
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1. Prepare the Pressure Sensor and an air sample for data collection.
a. Plug the Pressure Sensor into Channel 1 of the computer interface.
b. With the 20-mL syringe disconnected from the Pressure Sensor, move the piston of the
syringe until the front edge of the inside black ring (indicated by the arrow in Figure 3) is
positioned at the 10.0 mL mark.
c. Attach the 20-mL syringe to the valve of the Pressure Sensor. It has a white stem
protruding from the end of the sensor box. Attach the syringe directly to the white stem
with a gentle half-turn.
2. Prepare the computer for data collection by opening the experiment file in the launcher
window on the desktop.
On the Graph window the vertical axis has pressure scaled from 0 to 250 kPa, the horizontal
axis has volume scaled from 0 to 20 mL.
3. Click the "Collect" button to begin data collection.
4. To collect the pressure vs. volume data, it is best for one person to take care of the gas syringe
and for the other to operate the computer.
a. Move the piston to position the front edge of the inside black ring (see Figure 3) at the 5.0
mL line on the syringe. Hold the piston firmly in this position until the pressure value
stabilizes.
b. When the pressure reading has stabilized, click the "Keep" button. Type "5.0" in the edit
box. Press the ENTER or RETURN key to keep the data pair. Note: You can choose to
redo a point by pressing the ESC key (after clicking "Keep", but before entering a value).
c. Continue the procedure for volumes of 10.0, 15.0, and 20.0 mL.
d. Click "Stop" when you have finished collecting data.
5. In your notebook setup a table for the data that was recorded by the computer. In the data
table in your lab notebook, record the pressure and volume data. Add an additional column
with the column label- 1/V. This data is collected in Exercise 2B below.
6. a) If the data points appear to fall on a straight line you can apply the “Linear regression”
function to the data. The results will display the slope of the “best-fit” straight line and its
correlation factor. (If the data is distributed perfectly on a straight line it will have a
correlation factor of “1.0”.) You may need to sort your data before applying the function.
b) To obtain a “best-fit” line that suits your data click on the Analyze menu and select
“Linear fit.”
c) If the straight line does not fit your data select the ”Curve Fit“ menu item. In the resulting
dialog box click on the inverse function and select ”Try Fit“ and click ”OK.“
7. Sketch this plot in your lab notebook.
In your lab notebook record the file name with a short description of what the file represents and
the location. A couple of statements and a sketch of the figure are necessary.
E.2A
After formatting the graph in the LoggerPro application, copy and paste it into a
new Word document for Exercise 2. Write a caption beginning “Figure 1. Pressure
vs. volume of air” and save a copy of both the LoggerPro™ document as well as the
Word™ document to your flash drive before moving on to the next part of the
exercise.
This data will become the basis for a Results Section for Exercise 2. See
the What–to-Do Section at end this handout. Read Laboratory Guideline
Section VII. GUIDELINES FOR WRITING THE RESULTS AND
DISCUSSION SECTIONS OF A REPORT.
EXERCISE 2B
1. To explore a different type of relationship 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
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using LoggerPro, it is necessary to create a new column of data, reciprocal of volume, based
on your original volume data.
a. Remove the Linear Fit box and line from the graph by clicking on the upper-right
corner of the text box or reselect Linear Fit from the Analyze menu.
b. Choose "New Column > Formula" from the Data menu.
c. Enter "1/Volume" as the Long Name, "1/V" as the Short Name, and "1/mL" as
the Unit. Then click on the Definition tab.
d. Enter the correct formula for the column (1/volume) into the Equation edit box.
To do this, type in "1" and "/". Then select "Volume" from the Variables list. In
the Equation edit box, you should now see displayed: l/"Volume". Click "OK".
e. Click on the vertical-axis label, select "Pressure" (only), and click "OK". Click on
the horizontal-axis label, select "1/Volume" to be displayed on the horizontal
axis, and click "OK".
2. If the relationship between P and V is direct, the data points in the graph from section A
would lie on a straight line. On the other hand, if the relationship is inverse, the data points
in the graph from section B would lie on a straight line. Examine your graphs to see which
relationship better describes your data (minor, random deviations from a straight line are
OK).
3. For this plot try a linear fit. Under the Analyze menu select “Linear Fit.
4. Record the data in your notebook table.
5. Sketch this plot in your lab notebook.
To SAVE this data simply select the SAVE command from the FILE menu. After the dialog box
appears click on the button designated DESKTOP. Give your data file a name using the following
format:
Lastname_Exp#_E2.cmbl
(Your last name underscore experiment number underscore exercise (or section) number dot cmbl)
Note: Use this naming format for all files saved on Chemistry Lab Computers.
Click the SAVE button. You can transfer your document to a flash drive after quitting from the
program or email the files to your personal mailbox. Always save your data in more than one
location.
In your lab notebook record the file name with a short description of what the file represents and
the location. A couple of statements and a sketch of the figure are necessary.
E.2B After formatting the graph in the LoggerPro application, copy and paste it into the
open Word document. Write a caption beginning “Figure 2. Pressure vs. inverse
volume of air”. Show these two plots to your CA and save a copy of both the
LoggerPro™ document as well as the Word™ document to your flash drive with
the data from Part A.
This data will become the basis for a Results Section for Exercise 1. See
the What–to-Do Section at end this handout. Read Laboratory Guideline
Section VII. GUIDELINES FOR WRITING THE RESULTS AND
DISCUSSION SECTIONS OF A REPORT.
QUESTIONS (THESE MUST BE COMPLETED IN LAB)
Exercise 1
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Q.1. What temperature is numerically the same on both the Celsius and
Fahrenheit temperature scales? Show this mathematically using Eq. 1.
Exercise 2 (You need to display the plots on the computer to help answer questions.)
Q.2. Using the P vs. V graph from Section A, extrapolate your data to a volume of
2.5 mL (draw it). Rescale your plot to fit the data in the entire plot area. What
pressure does this correspond to on the graph?
Q.3. Using the P vs. 1/V graph from Section B, do a similar extrapolation to 2.5
mL. Rescale the plot. What pressure does this correspond to on the graph?
Q.4. Which of these two values is likely to be the most trustworthy? Why?
WHAT TO DO
BRING TO LAB:
1. Print a copy of this experiment, read it and bring it to your laboratory class.
2. Bring your Lab Notebook with the PreLab assignment completed (See “PreLab
Assignment” below). Your PreLab will be evaluated at the beginning of lab.
You will not be allowed to do the experiment without the prelab assignment
completed.
The lab notebook can be purchased during the week for $15.00 (check –to:
U.P.S. or cash-correct change appreciated) from SAACS or the Chemistry
Administrative Assistant.
3. Bring Goggles and appropriate footwear. Approved goggles are available in
Bookstore.
4. Bring a flash drive for obtaining a copy of the LoggerPro™ Installer and for
saving data files and documents generated in the laboratory.
5. To Be Turned in From Exp. 2- Copper Chemistry:
Be sure the assignment is removed from notebook and stapled before
coming to lab.
a. The First Page(s) must be the page with the answer to the all of the
questions.
b. The second page must be the Data Table and Calculations.
c. The remaining pages will be all the “copy” pages that contain your
Reactions and observations, in alphabetical order.
PreLab Assignment (Experiment 3 Spreadsheets…) - Carefully read the
experiment. Fill in the "Title bar" to include the experiment number, title, your name,
date, lab section, and CA's name. This information should be included on each page in
your laboratory notebook for all parts of this experiment.
In lab: Copy the appropriate LoggerPro™ Installer to your flash drive for
installing on your home computer.
Complete the Exercises 1 and 2. Save the worksheets from these exercises onto the
desktop using proper naming format for transferring to your flash drive or email.
Show the Word™ documents to your CA before moving to the next exercise. The
graphs and worksheets will need to be included in your Results section and the
questions answered in your laboratory notebook to be handed in net week.
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(Exercise 1) The aim of this Exercise is for you to become familiar with a
spreadsheet program. Answer Q.1. and save your Excel™ worksheet and the
Word™ document to your flash drive for working with at home.
(Exercise 2A/2B) The aim of this Exercise is to learn data collection and
processing using the LoggerPro™ application. Collect P vs. V data and using the
plotting in LoggerPro™ answer the Questions (Q.2. – Q.7) while in the application.
Save your LoggerPro™ worksheet and the Word™ document to your flash drive
for working with at home. While in lab copy the appropriate version of the
LoggerPro™ Installer to your flash drive and install on your own computer. Need
to save E.2A and E.2B (Plots from LoggerPro™).
Printing results in the Chemistry lab will not be possible so you will have to
save your worksheets and charts to your flash drive for continued formatting and
printing from your computer.
Read Laboratory Guideline Section VII. GUIDELINES FOR
WRITING THE RESULTS AND DISCUSSION SECTIONS OF A
REPORT.
At Home after lab:
Install the LoggerPro™ application on your computer and go online to
www.vernier.com and download the latest version of LoggerPro™. Update the copy
on your computer before continuing.
Prepare and hand in a formal Results section for Exercise 1 and separate formal
Results section for Exercise 2, Parts A and B. Each Results section should have a
separate and proper Title.
Exercise 1-Copy and paste the table and plot, properly titled and formatted, into a
Word document; “Exercise 1. Celsius and Fahrenheit Results”
Exercise 2 -For Exercise 2 Use the ”Table“ formatting to construct the data table
for Exercise 2A and 2B and copy and paste the plots, properly titled and formatted,
into a Word document titled “Exercise 2. Pressure and Volume Results”.
For both Results sections you will need to write the text for a formal Results
section as well as paste the Excel™ or LoggerPro™ plots from the experiment and add
a proper caption. The completed Results sections are due in lab next week at the start
of lab.
The Results section of a paper must always begin with a few sentences describing
the contents of the various tables and figures, referred to by number, as well as any
relevant information that does not fit into tables. Your objective is to tell the reader
where to find specific data. This text must not be redundant; don’t put data in both
text and tables.
To Be Turned in Next Lab:
hand-in all of your notebook “copy” pages associated with this laboratory. Please
include the answers to all the questions compiled together on the last copy page(s).
You may need to display your plots on your computer to help answer questions.
In addition Separately hand-in the printed pages (a Word document from Exercise
1 (result, table and plot) and a Word document from Exercise 2 (including results,
two LoggerPro™ plots and a data table).
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APPENDIX
GENERAL INSTRUCTIONS ABOUT SPREADSHEETS
A spreadsheet is an array of addressable memory locations of undefined variable
type. Each cell is addressed by a letter for the column and a number for a row. When
you select a cell and type data to put into it, you will need to define the formatting
you want for that data. Unfortunately, the default formatting is rarely the most
appropriate. For example, when you type in a number it is entered as “general” data,
with no set number of decimal places, and is right-justified. So if you entered 12.000, it
would be displayed as 12. Also, typing 12.011 g/mol would not be recognized as a
number usable in calculations because of the “g/mol”. In addition, if this were
entered below a cell containing a heading it would probably not be directly below that
heading, and may be so dramatically misaligned as to be unclear which heading it
belongs to. Thus, simply typing in data is not enough. Every cell will need to have the
number type and the alignment defined. Fortunately, you can often select a block of
cells and define all of them at the same time.
A formula is entered into a cell by beginning with “=”, which signals the program
that the following characters define mathematical operations. You can use the
addresses of other cells as variables, which is the great power of spreadsheets. In
general, you can use the usual operators and parentheses, but often you will use
functions, such as average(), sum(), etc with cell addresses in the (). These can be
typed or constructed using a wizard as you like. It is often best to click a cell rather
than type it, but the caveat is that any other cell you click will be entered into the
formula until you type” enter”. When you fill a formula down or across, the variable
addresses increment unless it is marked as absolute. Thus B14 filled down becomes
B15; filled across it becomes C14. You can reference a cell as relative, for example, cell
B14, or as absolute in column $B12, row B$12 or both $B$12 ( on a PC, with the F4
function button) . When these are filled the absolute address does not change. Once a
formula is entered, you can see the cells addressed by double-clicking the cell.
When entering numbers, you will need to define it as a number and select the
number of decimal places displayed as needed by the significant figures of the data.
You do this by selecting the cell and then “format cells” either by menu or by icon.
Alternatively, you may wish to select scientific notation, however this is clumsy in
many places and it is often better to put data in the appropriate power of ten. For
example, if all your data is 10-9 g, label the heading as ng (nanogram) and multiply all
the numbers by 109. This makes for a much more readable set of data. It is easier to
compare 23.54 ng to 4.387 ng than 2.354 x 10-8g to 4.387 x 10-9g. While you are
formatting the number, also format the alignment to center.
To “Fill” down or across there are several options. First, when you click a cell you
will see one of three different crosses as the cursor. An outline cross is used to select
cells; a Maltese cross is used to move selected cells; and a solid black cross, visible
only when the cursor is on the lower right corner, is used to fill. With the solid cross
showing, move down or across while holding down on the mouse. On release, the
cells will fill with either a copy of the number in the cell or an increment of the
formula displayed as the result of the formula calculation. If you are filling a number,
with the cells still highlighted, you can select “Fill” from the Edit menu and then the
number being filled from the original cell can be set to a “Series” of various options as
evident from the dialog box. If you are filling a formula the cell references will
increment unless marked as absolute; any formatting is also filled. If you move the
cells to another location, the formula addresses move also, but this may not work well
if the references are not also moved by the same amount.
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