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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