James Robertson Chemistry 2220 Determining the pKa of Bromothymol Blue by spectrophotometry Abstract To determine the pKa of an acid-base indicator, specifically bromothymol blue, different amounts of both 0.1M NaOH and 0.1 M HCl were added to a solution of fixed concentration of bromothymol blue and the pH was monitored via pH meter. At different pH readings around the researched pKa of Bromothymol blue we measured absorbance of the buffer solution. By superimposing the absorbance graphs, two wavelengths of absorbance […]
