Spectrophotometer#1

Spectrophotometer#1 - Post-Lab Data Summary Note : some...

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Post-Lab Data Summary Note : some questions will display a variable like "nCount" or "SyInput" instead of an actual number in the data summary. Q# Question Text 4) Part I. Free Response 2 points. Why do we allow electronic instruments to warm-up before use? Your Answer: We allow electronic instruments to warm-up before use because the electronic devices require time to thermally stabilize. When everything is thermally stable, the temperature compensation won't be changing so the note won't change. If you start playing before things are thermally stabilized, you may hear the temperature compensation circuit work and change your note. Text Answers to be Scored by your TA 5) Part I. Free Response 2 points. Why is it important not to have fingerprints on the cuvette? Your Answer: You do this so that you get a more accurate reading of the solution. Text Answers to be Scored by your TA 6) Part I. Free Response 2 points. Why is it important to align the cuvette in the sample holder the same way each time? Your Answer: It is important to align the cuvette in the sample holder the same way each time so that you can get an accurate reading. This is due to how the light goes through and reads each solution. Text Answers to be Scored by your TA 7) Part I. Data Entry No Scoring. In Part I you prepared the standard solutions of BROMOTHYMOL BLUE. Please enter the precise concentration of the undiluted stock solution #1 of the BROMOTHYMOL BLUE in micromoles per liter. (This is your most concentrated (undiluted) standard solution for which you measured the absorbance.) Use 3 significant figures. Molarity (μmol/L) = Your Answer: 23.30 No Points Possible 8) Part I. Data Entry No Scoring. You diluted a portion of the BROMOTHYMOL BLUE standard solution #1 to make standard solution #2 . Please enter the precise volume of the bromothymol blue standard solution #1 in milliliters used to prepare
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standard solution #2. Your precision should be to a hundredth of a milliliter, e.g. 15.00 mL. Volume (mL) = Your Answer: 4.64 No Points Possible 9) Part I. Data Entry No Scoring. You diluted a portion of the BROMOTHYMOL BLUE standard solution #1 with the pH 8.0 buffer to make standard solution #2 . Please enter the total volume of the resulting bromothymol blue standard solution #2 you prepared. Your precision should be to a hundredth of a milliliter, e.g. 50.00 mL. Volume (mL) = Your Answer: 25 No Points Possible 10) Part I. Scoring scheme 3-3-2-1. Calculate and enter the molarity of BROMOTHYMOL BLUE standard solution #2 . You should report your molarity to 3 significant figures, e.g. 31.5 µmol/L. Molarity (µmol/L) = Your Answer: 4.31 You Scored 3 points out of 3 Possible 11) Part I. Data Entry No Scoring. You diluted a portion of the
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Spectrophotometer#1 - Post-Lab Data Summary Note : some...

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