Download RawData Sheet

Chemistry 103 Laboratory
Density of Solutions
Data Analysis Supplement
Reference: The Measurements/Density Lab handout picked up from the folder outside
your instructor’s office door.
Data: After you have made the measurements with either Coke or Dr. Pepper you need to
enter your data into the system. Remember to watch for the uncertainty and significant
figures.
Results: Whenever you retrieve data outside the lab (from chem.gmu.edu/modresults)
you will get an Excel spread sheet that contains your data and that of other students. You
will need to download this sheet and save it either on your C drive or a Floppy. Then use
Excel to do the required calculations.
Your lab report should include the following:
1. The Excel spread sheet that you download from chem.gmu.edu/modresults. Name
this downloaded Excel sheet “RawData” by going to the bottom left of the page
and right double clicking on the tab that says Sheet 1. This sheet shows the raw
data for the entire class. Make sure that you include units for each column. Below
is an example of a retrieved RawData sheet:
RawData Sheet
A
B
C
D
E
M_full_reg
M_full_diet M_empty_reg M_empty_diet
Brand
(g)
(g)
(g)
(g)
2 Dr. Pepper
520.245
479.852
38.320
37.728
3 Dr. Pepper
517.562
477.629
38.047
40.032
4
Coke
516.258
483.944
39.150
38.330
5
Coke
524.567
477.805
41.376
38.442
1
F
V_reg
(ml)
450
450
450
450
G
V_diet
(ml)
450
450
450
450
2. You need to show your calculated results in a separate Excel spread sheet called
“ClassResults”. Go to Sheet2 of the Excel Document and right double click on
the this tab and name the sheet ClassResults. Include units for each column.
Below is an example of a Class Results page:
ClassResults Sheet
A
1
2
3
4
5
6
7
Brand
Dr. Pepper
Dr. Pepper
Coke
Coke
Mean=
Std. Dev=
B
density_reg
(g/mL)
1.071
1.066
1.060
1.074
1.068
0.006
C
density_diet
(g/mL)
0.982
0.972
0.990
0.976
0.980
0.008
To make this page type “Brand” in cell A1. Starting from cell A2 type in the
names of sodas used (Dr. Pepper and Coke) for as many as data points there are in
the RawData sheet. In cell B1 type in “density_reg (g/mL)”. In cell B2 type in the
appropriate formula using the data in the RawData sheet to calculate density of
the regular sodas used. Copy this formula into cells below B2 by dragging down
the lower right corner of box B2. In cell C1 type in “density_diet (g/mL)”. In cell
C2 type in the appropriate formula using the data for the diet sodas in the
RawData sheet. Drag this formula down to the cells below C2 as explained above.
Type “Mean=” in cell A6 and “Std. Dev=” in cell A7. Then calculate mean and
standard deviation for column B and C as done in Excel Homework steps 9
through 12. For more information on how to enter formulas for mean and
standard deviation please refer to page 6 of Excel Tutorial.
3. You need to make a third Excel sheet called “MyResults” showing how far off
the values of density for the two sodas you used are from the class mean. Right
double click on the tab Sheet 3 and call it MyResults. Be sure to include the type
of sodas used. One method of comparison is %error. Take the value for the one
type of soda you used and use this formula to calculate the percent error:
%Error = ((your value for one type of soda - class mean for the same type of
soda)/(class mean))*100.
Below is an example of such sheet:
MyResults Sheet
1
2
3
A
Brand
Dr. Pepper
B
C
Percent Error
Regular
Diet
0.280
0.204
To complete this page type “Brand” in cell A1, and “the name of soda used in
your group” in cell A3. Type “Percent Error” in cell B1 (first press the space bar a
few times then type Percent Error so that it will include column C also). Type
“Regular” in cell B2 and “Diet” in cell C2. Then in cell B3 and C3 enter the
formula to calculate %error of your values for regular and diet sodas you used
respectively.
4. After you have obtained these values, start from cell A5 and write out the
formulas you entered to calculate density, mean, standard deviation, and %Error
for one of the sets. For instance, your formulas may look as follows if the cells
listed here were the ones you used:
Density = (RawData!B3-RawData!D3)/RawData!F3
Average = Average(B4:B8)
Standard Deviation = Stdev(B4:B8)
%Error=((B2-B6)/B6)*100