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UB BIO 201LLB - Lab2b_

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Tables 1-5: Enter the Excel formulas for Means (i.e. averages), pH changes, and Standard Deviations. IN ORDER TO RECEIVE CREDIT, YOU MUST ALWAYS ENTER FORMULAS CELL REFERENCES FOR CALCULATIONED VALUES. e.g. '=AVERAGE(A1:E1)' would be the average of the data values in cells A1 through E1, and '=A1-A8' would be pH change if your data were in cells A1 through A8. (Do not include the quotation marks, but the equal sign (=) must be included for all formulas.) Once you have the first formula correctly entered, you can copy and paste into the remaining cells of the same formula, as long as it is within the same table. For more information, see Lab Report Instructions or visit the Microsoft Office Excel support website.Table 1: WATERDrops HCl pH pH pH pH pH pH pH pH Mean pH Standard Deviation pH change: Enter =STDEV(B15:G15) into the cell below.0 7.03 7.02 6.99 7.00 7.01 7.02 7.03 7.01 7.015 2.34 2.33 2.30 2.33 2.31 2.37 2.31 2.33 2.3310 2.07 2.05 2.04 2.03 2.02 2.07 2.04 2.01 2.0415 1.91 1.90 1.90 1.89 1.91 1.90 1.88 1.86 1.8920 1.82 1.76 1.81 1.79 1.80 1.80 1.81 1.78 1.8025 1.74 1.70 1.72 1.73 1.70 1.74 1.75 1.69 1.7230 1.66 1.64 1.64 1.63 1.65 1.62 1.65 1.63 1.64pH change*: --> 5.37 5.38 5.35 5.37 5.36 5.40 5.38 5.38 5.37 0.015*Enter the formula, including cell references, to calculate INITIAL minus FINAL pH (e.g =B8-B14).Table 2: PHOSPHATE BUFFERDrops HCl pH pH pH pH pH pH pH pH Mean pH Standard Deviation pH change0 7.22 7.23 7.19 7.20 7.22 7.18 7.21 7.18 7.205 7.14 7.15 7.12 7.17 7.13 7.09 7.11 7.09 7.1310 7.06 7.06 7.03 7.04 7.01 7.01 7.04 7.03 7.0415 6.91 6.94 6.91 6.90 6.94 6.84 6.91 6.87 6.9020 6.81 6.85 6.84 6.83 6.85 6.83 6.89 6.86 6.8525 6.74 6.75 6.73 6.71 6.72 6.7 6.77 6.76 6.7430 6.56 6.57 6.58 6.56 6.58 6.55 6.56 6.52 6.56pH change: --> 0.66 0.66 0.61 0.64 0.64 0.63 0.65 0.66 0.64 0.018Table 3: Bio Buffer 3Sweet potatoDrops HCl pH pH pH Mean pH Standard Deviation pH change0 6.18 6.17 6.21 6.195 5.98 5.98 6.04 6.0010 5.80 5.79 5.83 5.8115 5.62 5.63 5.67 5.6420 5.44 5.46 5.52 5.4725 5.31 5.33 5.39 5.3430 5.20 5.21 5.29 5.23pH change: --> 0.98 0.96 0.92 0.95 0.031Table 4: Bio Buffer 4Apple JuiceDrops HCl pH pH pH Mean pH Standard Deviation pH change0 3.60 3.54 3.58 3.575 3.59 3.53 3.58 3.5710 3.58 3.54 3.59 3.5715 3.57 3.54 3.59 3.5720 3.57 3.53 3.60 3.5725 3.55 3.51 3.55 3.5430 3.54 3.52 3.52 3.53pH change: --> 0.06 0.02 0.06 0.05 0.023Table 5: Bio Buffer 4Orange JuiceDrops HCl pH pH pH Mean pH Standard Deviation pH change0 3.70 3.68 3.68 3.695 3.66 3.64 3.61 3.6410 3.63 3.63 3.60 3.6215 3.60 3.61 3.59 3.6020 3.56 3.55 3.54 3.5525 3.53 3.52 3.50 3.5230 3.49 3.46 3.43 3.46pH change: --> 0.21 0.22 0.25 0.23 0.021Table 6: Enter the correct cell references for each Mean pH after addition of the indicated amount of HCl for each of the solutions. e.g. enter =J8 into cell B70 for water after 0 drops HCl.Table 6: SUMMARY DATAMean pHDrops HCl Water Phosphate buffer Sweet potato Apple Juice Orange JuiceReplace 'Bio Buffers 1-3' with actual names of solutions0 7.01 7.20 6.19 3.57 3.695 2.33 7.13 6.00 3.57 3.6410 2.04 7.04 5.81 3.57 3.6215 1.89 6.90 5.64 3.57 3.6020 1.80 6.85 5.47 3.57 3.5525 1.72 6.74 5.34 3.54 3.5230 1.64 6.56 5.23 3.53 3.46Graph 1: Plot MEAN pH (y-axis) as a function of DROPS ADDED (x-axis) from Table6 using a straight marked X-Y scatter chart. For full credit, all 5 curves must be on THE SAME GRAPH, AND AXES MUST BE LABELED. (See Lab Report instructions or Excel online Help for more information.)Table 7: Enter the correct cell references for each Mean pH change and Stdev pH change from the data tables above to obtain the appropriate values (e.g. '=J15' for water, etc.)Table 7: REORGANIZED DATASolution Mean pH change Stdev pH changeWater 5.37 0.015Phosphate Buffer 0.64 0.018Sweet potato 0.95 0.031 Replace 'Bio Buffers 1-3' with actual names of solutionsApple Juice 0.05 0.023Orange Juice 0.23 0.021Graph 2: Graph Mean pH change from Table 6 for each of the biological buffers and the controls using a Column (i.e. Clustered Column) chart. Remember to enterthe cells containing Stdev values for +/- error bars, AND REMEMBER TO LABEL YOURAXES. (See Lab Report instructions or Excel online Help for more information.)Questions: Answer all questions below in the spaces provided."1. If your hypothesis for this experiment was ""Biological solutions buffer the pH change that occurs when acid is added,"" what are the independent and dependent variables? (0.25 pts each)"Independent: Biological solutions Dependent: pH change2. Assuming the hypothesis above, what would a negative result be for this experiment? For a negative result, would the pH change when acid is added? (0.5 pts)A negative result will occur if the buffer does not prevent a rapid change in pH3. Based on the hypothesis stated in 1. your answer to 2., what is a negative control for this experiment? What is a positive control? (0.25 pts each)Negative control: Water Positive control: Phosphate buffer4. Does the hypothesis appear to be correct? Explain, including in your explanation the results of the positive and negative controls. (0.5 pt)The hypothesis appears to be correct because water represents as a negative control, and the data show that the pH level in the water changes rapidly with the addition of more drops of HCl. And the positive control is phosphate buffer.The data show that the buffer prevents pH changes, it slows down the change.Tables 1-5: Formulas & cell references for Mean pH (0.5 pt):Tables 1-5: Formulas & cell references for Mean pH change and Stdev (0.5 pt):Table 6: Cell references for everything (0.25 pt):Graph 1: All data on one graph, scatter plot, labels (1 pt):Table 7: Cell references for everything (0.25 pt):Graph 2: All data on one graph, column graph ,stdev for error bars, labels(0.5 pt):Total for questions (1 pt):TOTAL (OUT OF 8):


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