Bromothymol blue is an indicator used to detect weak acids and bases in acidic solutions, it appears yellow, in basic solutions it is blue, and in mid ph ranges, it is green by determining the absorbance values of solutions at all of these extremes, the equilibrium constant (k c ) of this indicator can be calculated. For this experiment, we chose bromothymol blue, an indicator with a pka value of ~71 and a transitional range of 60 to 76 ph units first we added 1 ml of 01 m hcl to 15 ml of water to this solution we added 2 drops of bromothymol blue and measured the ph and the absorbance. Chem 112 pre lab quiz 11 experiment 14 determination of equilibrium constant tamu chem 112 spring 2015 study play during this experiment, you are going to measure the ph of a buffer solution containing the indicator bromothymol blue using: ∙ none of these ∙ ph paper.
During this experiment, you are going to measure the ph of a buffer solution containing the indicator bromothymol blue using: ∙ none of these. View lab report - chem 241 spectrophotometric determination of the pka of the acid-base indicator bromothymol blue from chem 241l at university of north carolina experiment 3.
Isosbestic point and equation of absorbance vs ph for a universal ph indicator for estimation at any point without necessitating an experiment in contrast, potentiometric titration requires spectrophotometric determination of the pka, isosbestic point and equation of absorbance vs ph for a universal ph indicator. To determine the pka of the acid-base indicator bromothymol blue using a spectrophotometer to measure the absorbance of different buffered solutions what does a larger ka mean equilibrium lies farther to the right and it is a stronger acid, smaller pka. Subsequently, this would indicate that bromothymol blue would be useful in a titration where the equilibrium point ph would be close to the ph of the color change of bromothymol blue 2 in order to carry out this experiment, a spectrophotometer will be used to determine the experimental pka of bromothymol blue.
Experiment #3: spectrophotometric determination of the pka of the acid-base indicator bromothymol blue 241l-410 room 405 ta: marc webb 2/13/16 pledge i pledge that i have not used someone else’s old or current lab report when writing this lab report i pledge that i did not collaborate with any other students and that the report i submitted here contains my own ideas, thoughts, observations. 3 use the ph meter to measure the ph of the ph 1, hydrochloric acid solution, the ph 13, sodium hydroxide solution, and the 10 solutions which were prepared in this step record the ph of each solution 4 using the scanning spectrophotometer, obtain and record spectra between 300 and 800 nm of the ph 1 and the ph 13 bromothymol blue solutions. In this experiment, spectrophotometry is employed to measure the pka of bromothymol blue, an acid-base indicator the indicator (hin) is a monoprotic acid and we.
In this experiment students learned how to analyze this information to calculate ka and pka of each solution, which varied in ph students used a spectrophotometer in the experiment to analyze the absorbance of different wavelengths of light passing through multiple solutions containing bromothymol blue. In the experiment the pka of bromothymol blue (3',3- dibromo-thymolsulfonephthalein) is determined by the two methods which have been discussed at ph less than 6, the indicator is yellow and at ph greater than 76, the indicator is blue. A simplified method for finding the pk a of an acid–base indicator by spectrophotometry this experiment yields ac curate results using equipment found in most general chemistry labs bromothymol blue, 010% methyl orange, 010% sodium salt.
A simplified method for finding the pk a of an acid–base indicator by spectrophotometry to illustrate one aspect of equilibrium, a new laboratory experiment on the measure-ment of an equilibrium constant was desired ideally, the ex-periment would 1 result in a reasonably accurate value of the equilibrium bromothymol blue, 010%. 004% bromocresol purple, 004% bromophenol blue, 004% bromothymol blue, 010% methyl orange, 010% sodium salt of methyl red, and 004% phenol red were obtained from aldrich chemical co the procedure for determining the pk a for bromophenol blue is described in detail conditions for determining the pk a values for the other indicators are tabulated.
Bromothymol blue is an indicator used in the experiment to signal a specific point in an acid-base reaction by changing color in this experiment students learned how to analyze this information to calculate ka and pka of each solution, which varied in ph.