Concentration from Absorbance Calculator
What is Concentration from Absorbance Calculator?
A Concentration from Absorbance Calculator is a tool used to calculate the concentration of a solution based on its absorbance, path length, and extinction coefficient. This type of calculator is commonly used in chemistry and biochemistry to determine the concentration of a solution by measuring its absorbance at a particular wavelength.
Formula
The formula used in the Concentration from Absorbance Calculator is:
C = A / (L * e)
Where:
- C is the concentration of the solution in molar (M)
- A is the absorbance of the solution
- L is the path length of the sample in centimeters (cm)
- e is the extinction coefficient of the compound in units of M^-1 cm^-1
Example
Suppose we have a solution with an absorbance of 0.5 at a wavelength of 280 nm. The path length of the sample is 1 cm and the extinction coefficient of the compound is 20,000 M^-1 cm^-1. To calculate the concentration of the solution, we can use the formula as follows:
C = A / (L * e) C = 0.5 / (1 * 20000) C = 0.000025 M
Therefore, the concentration of the solution is 0.000025 M.
How to Calculate
To use the Concentration from Absorbance Calculator, you need to follow these steps:
- Measure the absorbance of the solution using a spectrophotometer or colorimeter.
- Determine the path length of the sample in centimeters.
- Obtain the extinction coefficient of the compound in units of M^-1 cm^-1 from a reference source or literature.
- Enter the values of absorbance, path length, and extinction coefficient into the Concentration from Absorbance Calculator.
- Click on the “Calculate Concentration” button to obtain the concentration of the solution in molar (M).
FAQs
What is absorbance?
Absorbance is a measure of the amount of light absorbed by a substance at a particular wavelength. It is defined as the negative logarithm of the ratio of the intensity of incident light to the intensity of transmitted light through a sample.
What is the path length of a sample?
The path length of a sample is the distance that light travels through the sample in a spectrophotometer or colorimeter. It is usually measured in centimeters (cm).
What is extinction coefficient?
Extinction coefficient is a measure of how strongly a compound absorbs light at a particular wavelength. It is defined as the molar absorption coefficient (in units of M^-1 cm^-1) and is specific to each compound. It is often used to quantitatively describe the efficiency of a compound to absorb light.
