What is the Ka of bromothymol blue?

What is the Ka of bromothymol blue?

Bromthymol blue, an indicator with a Ka value of 1.0 x 10-7, is yellow in its HIn form and blue in its Inform.

What is the molar mass of bromothymol blue?

624.38 g/mol
Bromothymol blue/Molar mass

What is the pH range for bromothymol blue?

6.0 – 7.8
In other words the color of phenolphthalein changes perceptibly between about pH 8.3 and 10.5. Observe the actual color change for this indicator in Figure 14.9….14.9: Indicators.

Name Bromothymol blue
pKa 7.1
Effective pH range 6.0 – 7.8
Color Acid form Yellow
Basic form Blue

What Colour is bromothymol blue at pH 9?


Indicator Low pH color High pH color
Methyl red red green
Azolitmin red blue
Bromocresol purple yellow purple
Bromothymol blue yellow blue

How do you measure absorbance?

Absorbance is measured using a spectrophotometer or microplate reader, which is an instrument that shines light of a specified wavelength through a sample and measures the amount of light that the sample absorbs.

What is thymol blue indicator used for?

pH indicator
Thymol blue (thymolsulfonephthalein) is a brownish-green or reddish-brown crystalline powder that is used as a pH indicator. It is insoluble in water but soluble in alcohol and dilute alkali solutions.

Is thymol blue the same as bromothymol blue?

Bromothymol blue is synthesized by addition of elemental bromine to thymol blue in a solution in glacial acetic acid.

What is the color of the indicator thymol blue in?

Indicator pH Range color in base form
Thymol Blue 1.2 – 2.8 yellow
Methyl Orange 3.1 – 4.4 orange
Methyl Red 4.2 – 6.3 yellow
Thymol Blue 8.0 – 9.6 blue

How do you read absorbance readings?

Interpret the absorbance value. Absorbance can range from 0 to infinity such that an absorbance of 0 means the material does not absorb any light, an absorbance of 1 means the material absorbs 90 percent of the light, an absorbance of 2 means the material absorbs 99 percent of the light and so on.

What is the absorbance spectrum of bromothymol blue?

Figure 1 shows the absorbance spectra of the reference solutions, the blue spectrum from the solution with pH 2.2 and the red spectrum from the solution with pH 11.47. These provide the wavelengths at which bromothymol blue has peaks, one at 435.5 nm from the solution of ~100% HIn, and another at 614.5 nm from the solution of ~100% In –.

What is the equilibrium constant of a bromothymol blue indicator?

Bromothymol blue is a chemical indicator that appears yellow in very acidic conditions, blue in basic conditions, and green in mid pH ranges. This experiment will determine the equilibrium constant of this indicator by comparing the absorbance of a buffer solution containing bromothymol blue at its yellow, blue and green states.

What is the PK C of bromothymol blue?

Thus, the calculated equilibrium constant for bromothymol blue is 1.12 , with a pK c value of 6.95. The error in pH values was determined to be ± 0.03 units, and for all absorbance values, there is an error of ± 0.002. With these error values, a total standard deviation associated with K c can be calculated.

Is bromothymol blue solid or liquid?

It is typically sold in solid form as the sodium salt of the acid indicator. Bromothymol blue acts as a weak acid in a solution. It can thus be in protonated or deprotonated form, appearing yellow or blue, respectively. It is bright aquamarine by itself, and greenish-blue in a neutral solution.