Pipetting Day

Today, July 13, we did an experiment to see if pipettors were really accurate. First of all, we set our pipettor to 100 mL and then filled it up with red dye. Then we released the red dye from the pipettor into a test tube. We repeated this five times. Next we added 3 mg of disel water into each test tube, plus one extra test tube that contained no red dye. Then we measured the absorbance at 560 nm wavelength and recorded the data. Next we weighed the disel water. The data is listed below, and as you can see, we weren't very accurate.

• • Volume    Weight    Absorbance
    100           0.102     1.231
    100           0.10       1.259
    100           0.102     1.238
    100           0.124     1.235
    100           0.097     1.652
    average     0.105     1.323 
     std dev     0.0108  0.1843
      percent  10.3015 13.9255 
     
     

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