1. What is a Wavelength given Energy of Reaction Calculator?

Definition: This calculator determines the wavelength of light corresponding to the energy absorbed in a photochemical reaction.

Purpose: It helps chemists and physicists understand the relationship between energy and wavelength in photochemical processes.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

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

Explanation: The formula calculates the wavelength of light that corresponds to the energy absorbed per mole of substance in a photochemical reaction.

3. Importance of Wavelength Calculation

Details: Knowing the wavelength helps determine what type of light will be effective for a photochemical reaction and provides insight into the energy requirements of the process.

4. Using the Calculator

Tips: Enter the energy absorbed in the photochemical reaction in Joules. The energy must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: Why do we use Avogadro's number in this calculation?
A: Because we're calculating for one mole of substance undergoing the photochemical reaction.

Q2: What are typical energy values for photochemical reactions?
A: Most photochemical reactions involve energies between 100-500 kJ/mol (100,000-500,000 J/mol).

Q3: What wavelength range does this typically correspond to?
A: For visible light, wavelengths range from about 400-700 nm (4×10⁻⁷ to 7×10⁻⁷ m).

Q4: How does wavelength relate to reaction energy?
A: Shorter wavelengths correspond to higher energy photons, which can drive more energetic reactions.

Q5: Can this be used for single molecules rather than moles?
A: Yes, but you would need to omit Avogadro's number from the calculation.