Experiment 26 report - Experiment 26 pKa of Bromothymol...

This preview shows page 1 - 3 out of 4 pages.

Experiment 26pKaof Bromothymol Blue IndicatorbyCollin BrunsChem 114L-10 Bremansu Osa-AndrewsMarch 3, 2016Mitchell AdamsThe pKaof bromothymol blue indicator was determined at 617.10 nm and 440.40 nm using spectrophotometric measurements at 294.8 K. The pKawas calculated to be 7.08 ± 0.09 at 440.40nm and 7.03 ± 0.08 at 617.10 nm. When compared to the given pKavalue of 7.10 at 298.15 K, these calculated values yield percent errors of 0.28% at 440.40 nm and 0.99% 617.10 nm. Possible sources of error include using the same pipette for each solution which may cross-contaminate the solutions and not allowing each solution to reach equilibrium before taking the pH readings.
PROCEDURE: Hirko, R. Chemistry 114L General Chemistry II Laboratory, Ninth Edition;bluedoor: Minneapolis, 2015; Experiment 26.Table 1. pK of bromothymol blue indicator at 294.8 K and 617.10 nm.RESULTS: The values collected in Table 1 and Table 2 were used to calculate the pKaof bromothymol blue indicator at their respectiveTable 2. pK of bromothymol blue indicator at 294.8 K and 440.40 nm. wavelengths. Figure 1 shows the wavelength versus absorbance values of bromthymol blue runs 1 through 9. That spectrum in the background is the colors of light that are apparent at that particular wavelength. Using Equation 1,pKa=pH+logAAHALA(1)where A represents the absorbance of the solution at a particular pH, AH represents the absorbance of the solution at high pH value of the wavelength and ALrepresentsthe absorbance of the solution at BeakerRunpHAColorAHALLog A-AHAL-A

Upload your study docs or become a

Course Hero member to access this document

Upload your study docs or become a

Course Hero member to access this document

End of preview. Want to read all 4 pages?

Upload your study docs or become a

Course Hero member to access this document

Term
Spring
Professor
NoProfessor
Tags
pH, Pk, Bromothymol Blue Indicator, Collin Bruns

  • Left Quote Icon

    Student Picture

  • Left Quote Icon

    Student Picture

  • Left Quote Icon

    Student Picture