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The molar absorptivity of crystal violet can be determined using Beer's Law. Beer's Law is A=E*c*l where A is absorbance, E is the molar absorptivity, C is the concentration of the crystal violet, and l is the path length. Path length is how long the light has to travel through the solution. If you can find the absorbance of a certain concentration by using a spectrophotometer, where the path length is 1 cm, then you know all the variables and are able to solve for the molar absorptivity.
For example, the measured absorbance of 2.5x10^-5 M CV (crystal violet) is 1.64 with a path length of 1 cm. This means
1.64=E*(2.5x10^-5)*1
E=1.64/(2.5x10^-5)
E=65600
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Why is hydrochloric acid added in a molar absorptivity of benzoic acid?
It is added to protonate the sodium benzoate.
What is the extinction coefficient of crystal violet?
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Crystal violet acid-base indicator?
Yes it is.
What will be the color change of crystal violet at different pH?
Crystal violet is used in Gram's method of bacteria classification. At a pH of 1.0, the solution turns green, and when in a strongly acidic solution, it turns yellow.
Why didn't you need to know the molar absorptivity of the equilibrium mixture or the path length for the calculations you did in this experiment?
Simple. Because you have the percent transmittance (%T).Instead of using the Beer-Lambert Law:A=ϵbcyou use equation 7:A=2.00−log(%T)
Why can you not measure the molar absorptivity of the food dyes?
You can.
How does the molar absorptivity depend upon the concentration mole per L of the dissolved solute?
Molar absorptivity is completely independent of concentration of a substance as Molar absorptivity is represented by epsilon and is a constant. Absorbance of light is what is dependent upon concentration and will go down as concentration goes down and increase as concentration increases.
Why is hydrochloric acid added in a molar absorptivity of benzoic acid?
It is added to protonate the sodium benzoate.
What is the secondary stain in gram stain procedure?
It is crystal violet & stains all cells purple.
What Beers law?
Beer's law says that absorbance of a molecule or solution is:A = a*b*cwhere A is the absorbance, "a" is the absorptivity (in units of per molar per cm, M-1 cm-1), "b" is the path length (in units of centimeters, cm), and "c" is the concentration (in units of molar, M). The absorptivity, is also commonly known as epsilon.That means that the absorbance is linearly proportional to the thickness of the sample, the concentration of the absorbing medium, and the absorptivity, which is a measure of a given molecule's ability of absorb light.See the Web Links for more information.
What is gentian violet?
Traditional antifungal drugs such as.gentian violet (also known as crystal violet)
What is the molar absorptivity of Cu2 plus at 620 nm given that the cuvettes used in lab had a pathlength of 1.00 cm with a concentration verse absorbtivity curve of y equals .727x plus .0557?
.727/g*M, slope is molar absorbtivity
What is crystal violet iodine complex?
In Gram staining procedure during bacterial staining , iodine forms a complex with crystal violet stain which stains Gram positive bacteria blue to violet .
What is the extinction coefficient of crystal violet?
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Why is Iodine used in Gram staining?
Iodine is added as a mordant to enhance crystal violet staining by forming a crystal violet-iodine complex.
Which formula do you use for the calculation of absorptivity?
ANSWER:"e is a measure of the amount of light absorbed per unit concentration".Molar absorbtivity is a constant for a particular substance, so if the concentration of the solution is halved so is the absorbance, which is exactly what you would expect.The formula for the molar absorptivity is given as followings:A=ecle=A/cle = the molar absorptivitywhere A is known as the A is known as the absorbance, l measures the length of the solution the light passes through,c is theconcentration of solution in mol /dm^3.Remember that the absorbance of a solution will vary as the concentration or the size of the container varies. Molar absorptivity compensates for this by dividing by both the concentration and the length of the solution that the light passes through. Essentially, it works out a value for what the absorbance would be under a standard set of conditions - the light travelling 1 cm through a solution of 1 mol dm-3. a
Crystal violet acid-base indicator?
Yes it is.
