A sample containing 2.7 x 10-4 M green fluorescent protein shows an absorbance of 0.651 at 509 nm. Calculate its molar absorptivity constant (ε).
To calculate the molar absorptivity constant (ε), we use the Beer-Lambert Law:
A = ε * c * l
where:
A is the absorbance,
ε is the molar absorptivity constant,
c is the concentration (in M),
l is the path length (in cm).
Given:
A = 0.651,
c = 2.7 x 10^(-4) M (or 2.7e-4 M),
l = unknown (we will solve for it).
We need to rearrange the equation to solve for ε:
ε = A / (c * l)
We need the value for l to calculate ε. The path length, l, is commonly 1 cm.
ε = 0.651 / (2.7e-4 M * 1 cm)
ε = 0.651 / 2.7e-4
ε ≈ 2.411 x 10^3 M^(-1) cm^(-1)
Therefore, the molar absorptivity constant (ε) is approximately 2.411 x 10^3 M^(-1) cm^(-1) for the sample containing 2.7 x 10^(-4) M green fluorescent protein.
To calculate the molar absorptivity constant (ε), you can use the Beer-Lambert Law, which relates the absorbance (A) of a sample to the molar concentration (C) and the path length (l) of the sample cell:
A = ε × l × C
In this case, you have the absorbance (A) and the molar concentration (C). You need to calculate ε.
Given:
Absorbance (A) = 0.651
Molar concentration (C) = 2.7 x 10^(-4) M
Path length (l) = ?
We need to calculate the molar absorptivity constant (ε). Rearranging the Beer-Lambert Law equation, we get:
ε = A / (l × C)
Let's calculate ε.
ε = 0.651 / (l × 2.7 x 10^(-4) M)
To calculate ε, we need the path length (l). However, it is not provided in the given information. The path length usually refers to the width or height of the cuvette used in spectroscopic measurements. You need to provide the path length to calculate ε accurately.