1. What is Concentration of Solution given Intensities of Radiation?

Definition: This calculator determines the concentration of a solution based on the intensities of incident and reflected radiation, cell thickness, and molar extinction coefficient.

Purpose: It's used in spectroscopy and analytical chemistry to quantify solute concentrations using light absorption measurements.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( c \) — Concentration of solution (mol/m³)
• \( I_i \) — Intensity of incident radiation (W/m²·sr)
• \( I_r \) — Intensity of reflected radiation (W/m²·sr)
• \( l \) — Thickness of cell (m)
• \( \epsilon \) — Molar extinction coefficient (m²/mol)

Explanation: The logarithm of the intensity ratio is divided by the product of cell thickness and molar extinction coefficient.

3. Importance of Concentration Calculation

Details: Accurate concentration measurements are essential for chemical analysis, quality control, and research applications.

4. Using the Calculator

Tips: Enter all radiation intensities, cell thickness (default 50 nm), and molar extinction coefficient (default 0.0019 m²/mol). All values must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: What is the molar extinction coefficient?
A: It's a measure of how strongly a chemical species absorbs light at a particular wavelength.

Q2: How do I measure radiation intensities?
A: Use a spectrophotometer to measure light intensity before and after passing through the sample.

Q3: What units should I use for cell thickness?
A: The calculator uses meters, but you can enter values in nm (1 nm = 1×10⁻⁹ m).

Q4: Can I use this for any wavelength?
A: Yes, but you must use the extinction coefficient specific to your wavelength.

Q5: What if my solution is very concentrated?
A: For high concentrations, you may need to dilute your sample for accurate measurements.