1. What is Energy of Photochemical Reaction in terms of Wavelength?

Definition: This calculator computes the energy absorbed by one mole of a substance undergoing a photochemical reaction based on the wavelength of light.

Purpose: It helps chemists and photochemists determine the energy required for photochemical reactions.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( E \) — Energy in Joules
• \( [Avaga-no] \) — Avogadro's number (6.02214076×10²³ mol⁻¹)
• \( [hP] \) — Planck constant (6.626070040×10⁻³⁴ J·s)
• \( [c] \) — Speed of light (299792458 m/s)
• \( \lambda \) — Wavelength in meters

Explanation: The formula calculates the energy per mole of photons for a given wavelength.

3. Importance of Photochemical Energy Calculation

Details: Accurate energy calculation is crucial for understanding reaction mechanisms, designing photochemical processes, and predicting reaction outcomes.

4. Using the Calculator

Tips: Enter the wavelength in meters (default 2.1×10⁻⁹ m for UV light). The value must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: What is Avogadro's number used for here?
A: It converts the energy from per photon to per mole of photons, which is more useful in chemistry.

Q2: What's a typical wavelength range for photochemical reactions?
A: Most photochemical reactions use UV (100-400 nm) or visible light (400-700 nm).

Q3: How does wavelength affect the energy?
A: Shorter wavelengths have higher energy photons, following the inverse relationship in the formula.

Q4: Can I use this for single photon energy?
A: Yes, just divide the result by Avogadro's number to get energy per photon.

Q5: What units does this calculator use?
A: All calculations are in SI units - meters for wavelength and joules for energy.