Page 1 of 5. 1: Reaction Stoichiometry Name: Using Excel for Data Analysis Class: Date:

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1 1: Reaction Stoichiometry Name: Using Excel for Data Analysis Class: Date: Page 1 of 5 Part 1: Warming Up 1. Open Excel from the start up menu. (Disclaimer: If you choose to use Google Sheets, some of these steps might be done differently. If you run into trouble, try search online for how to do it in Sheets.) 2. If prompted, select Blank workbook as the template. 3. Type the following data into the workbook. Mass filter paper Mass filter paper and solid Double click the top of the column so the text doesn t run over the edge of the box. I typed mine into column A and column B. Part 2: Adding and Subtracting 5. At the top of the next column (column C for me), type Mass solid (g) to name the column. 6. Now we want to calculate the mass of the solid when the filter paper is subtracted out. (For me, that s subtracting the data in column B from the data in column A). Right under where you named your column, (box C2 for me), type an equal sign and leave the cursor in the box. Now click on the first column you want to subtract, then a minus sign, then click the second column you want to subtract. My command reads =B2-A2. (If you wanted to add, use a plus sign.) 7. Hit enter. You can double click the cell to edit it if you mess up. 8. Click on the cell you just typed. Look for the green box in the lower right hand corner. Hover the cursor over the green box until it changes to a black cursor. Click down and drag all the way down to the bottom of the data. 9. Check your work to make sure you calculated correctly. Your data table should look something like this.

2 Page 2 of 5 Part 3: Multiplying and Dividing 10. At the top of the next column (column D for me), type Mass solid (mg) to name the column. 11. We now want to convert grams of solid (column C) into milligrams of solid (column D). To do this, we need to multiply the grams of solid (column C) by 1000, as there are 1000 mg in 1 g. Right under where you named your column, (box D2 for me), type an equal sign and leave the cursor in the box. Click on the grams of solid column, type an asterisk then My command reads =C2*1000. (If you wanted to divide, use a slash (/). 12. Click and drag down the little green box, as in step Check your work to make sure you calculated correctly. Your data table should look something like this.

3 Page 3 of 5 Part 4: Try it Yourself 14. Type in the following data. For me, I typed in columns E through H. Start Volume End Volume Sample Volume (ml) Sample Volume (L) Try to repeat the same procedure you just did in Part 1 and Part 2, this time calculating the volume of water sample in L. If you did it correctly, it will look like this.

4 Page 4 of 5 Part 5: Finding the Hardness 16. Name the next two columns as CaCO3 (mg/l) and Final CaCO3 (mg/l). For me, this is box I1 and J Now we want to calculate the mg/l of CaCO3 in our sample. Right under where you named your column, (box I2 for me), type an equal sign and leave the cursor in the box. Now click on the column you want as the numerator (box D2), type a slash, then click the column you want as the denominator (box H2). My command reads =D2/H Click and drag down the little green box, as in step The sample you studied was concentrated by a factor of 100 for analysis. Thus, the answer we get for mg/l of CaCO3 is too large by 100 times. To get the final (correct) hardness, we must divide our answer by 100. Click on the first box under the Final CaCO3 (mg/l) box (box J2) and type an equal sign, click on the first box under mg/l of CaCO3 (box I2), type a slash, then 100. My command reads =I2/ Click and drag down the little green box, as in step If all is well, your work should look like this:

5 Page 5 of 5 Part 6: Finding the Average and Standard Deviation 22. Choose a blank box on the page. I choose J Type an equal sign, the word AVERAGE and an open parenthesis. Then click and drag to select the cells you want to take the average of, then type another parenthesis to close. Hit enter. My command read =AVERAGE(J2:J6), and my answer is Label the box to the left of this value (box I7 for me) as Avg. Hardness. 25. Directly under the last box you choose in step 22 (J8 for me), type an equal sign, then type stdev.p followed by an open parenthesis. Then click and drag the cells same cells you took the average of, then type another parenthesis to close. Hit enter. My command read =stdev.p(j2:j6), and my answer is Label the box to the left of this value (box I8 for me) as Std. Dev. 27. If all is done correctly, it will look like this: Part 7: Cleaning It Up 28. Make the 3 in CaCO3 subscript. Double click in the cell and highlight the 3 with the cursor. Right click and select Format Cells. Check off the appropriate box and click OK. 29. Go back and make sure each column gives the units in parentheses. 30. Are some boxes showing the wrong sig figs? Select those boxes by clicking and dragging. With the boxes highlighted, adjust the decimal places using the and buttons from the Number menu. 31. Report your final answer as the average hardness ± standard deviation. The precision in the average dictates what precision you can report for the standard deviation. For this data, the average hardness is 357.1±1.2 mg/l. 32. Put lines around the boxes by highlighting them all and clicking the button under the Font menu. 33. Point out final answers by selecting their boxes and clicking the button under the Font menu. I did this for the Avg. Hardness and Std. Dev. boxes. 34. Save your work in an organized way! Save these directions! 35. For your post-lab: copy and paste by selecting all cells, pressing Ctrl C to copy, and press Ctrl V to paste into your document.