Concentration of Dye During the Reaction Start with the variation in concentration during the reaction. To generate this graph hold down the left mouse button and highlight the data in column A by dragging the cursor from A2 to A17. Release the mouse button. Hold down the Control button to enable multiple data selection. Now highlight the data in column C. All the data in columns A and C should now be highlighted. Release the Control. Now go to the menu bar and choose “INSERT”. Select “CHART”. (Alternatively you can click on the Chart Wizard icon (a histogram) if it is in the menu bar at the top of the screen). A box appears (CHART WIZARD) on the screen that gives you all the different choices for graphs. You should select “XY (Scatter)”. Click on “NEXT”. A little tiny graph should appear on the screen. This is the “preview” of the graph. Click on “NEXT” again. You now see a table with five different options. All you need to modify are the titles and the legends. Click on “TITLES”. Type in the title of the graph and also the labels for the axes. Remember to add the scaling factor to the y-axis label. (At this point just type 106 we will make the 6 a superscript later.) Click on “LEGENDS” and delete the “Show Legend” check mark. Click on “NEXT”. There is one last thing that EXCEL needs to know before it can generate the graph. It wants to know where you want to put the graph. Click on “AS NEW SHEET”. This means you want EXCEL to plot the graph on a separate sheet of paper; otherwise, EXCEL will plot the graph and print the data on the same piece of paper. (Like in the sample data sheet, but not how you want it for your lab report.) Click on “Finish” to complete the graph. Congratulation, you have just finished plotting a graph using EXCEL. Your graph should look almost like the one on the next page. Using other features in EXCEL you can now manipulate your graph to conform with standard scientific practice. There are three things to adjust: the color of the main area of the graph, the size of the fonts for the labels and title, and the superscript for the scaling factor. (1) The first thing to do is to change the background to white so that you can more clearly see your data, which is the important feature of the graph. Move your cursor to the gray background and double click. A pop-up window titled “Format Plot Area” will appear. Under the Patterns tab, change the color of the Area from gray to white. (2) To change the font size of the title or the axes, double click on the label. Select the tab labeled “Font” to make any changes you wish. (3) To change a portion of the text in a label or an axes, single click on the label you want to change. A box will appear around the label, then click again. You now can change the text. For the exponent in the concentration label, highlight just the 6 in the number 106. Then right click and select “Format Axis Title”. You will now get the same menu as in (2) to change this number to a superscript. Your graph should now look like the one on the next page. Select SAVE and send it to the printer. 4CONCENTRATION OF DYE DURING REACTION0.002.004.006.008.0010.0012.0014.000 50 100 150 200 250 300 350 400 450 500TIME (sec)6 Plots of the data as first-order and second-order reactions. To return to your data, select the tab at the bottom of the screen called “Sheet 1.” Repeat the process above to graph the data in column D as a function of time. In addition to the adjustments you made for the first graph, one additional item is needed in this plot: You need to move the scale for the x-axis to the bottom of the graph. The default position for EXCEL is 0 on the y-axis. Place your cursor on the y-axis grid line. It will show boxes at either end. Under the Format menu choose Selected Axis, and then select the tab Scale. Change “Value (X) axis Crosses at: from 0 to –4.0 This will place the scale in the correct place on the graph. Calculation of the order of the reaction. From the three graphs you can conclude that the reaction is first order in Brilliant Blue FCF because the plot of ln [Dye] vs time is linear. Let’s push EXCEL just a little further to do one more calculation for us in getting to the rate constant. Return to Chart 2, the plot of ln [dye] vs time. On the menu bar select Chart and then Trend Line. Under the tab Type select Linear. The regression line will appear. Now double click on the line and under the Format menu select Selected Trendline. Under Format Trendline select the Options tab. Check Display equation on graph. Once you have the equation on the graph, you can select it, move it, and increase the font as you have done for other labels and text. When you have finished plotting all the graphs, complete the following self-evaluation form and turn it in to your TA BEFORE you leave the computer room. 56 Name: ________________________________ TA: __________________________________ Need Mastered More Practice Able to use EXCEL to input data properly ________ ________ Able to use EXCEL to perform mathematical operations on a data set ________ ________ Able to COPY/PASTE/EDIT data in the EXCEL spreadsheet ________ ________ Able to manipulate column formats in EXCEL ________ ________ Able to use "Chart Wizard" in EXCEL to generate graphs ________ ________ Able to put in titles and axis labels on graphs ________ ________ Able to manipulate axis scales and gridlines on graphs ________
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