1. What is the Photon Energy Equation?

The photon energy equation calculates the energy of a photon in kJ/mol using Planck's constant, frequency, and Avogadro's constant. It provides a way to convert individual photon energy to molar energy for chemical applications.

2. How Does the Calculator Work?

The calculator uses the photon energy equation:

Where:

• \( E \) — Photon energy (kJ/mol)
• \( h \) — Planck's constant (6.626 × 10⁻³⁴ J s)
• \( f \) — Frequency (Hz)
• \( N_A \) — Avogadro's constant (6.022 × 10²³ mol⁻¹)

Explanation: The equation converts the energy of individual photons to molar energy by multiplying by Avogadro's number and converting from joules to kilojoules.

3. Importance of Photon Energy Calculation

Details: Calculating photon energy is crucial for understanding photochemical reactions, spectroscopy, quantum chemistry, and various applications in physics and materials science.

4. Using the Calculator

Tips: Enter Planck's constant in J s, frequency in Hz, and Avogadro's constant in mol⁻¹. Default values are provided for Planck's constant and Avogadro's constant, but you can input custom values if needed.

5. Frequently Asked Questions (FAQ)

Q1: Why divide by 1000 in the equation?
A: The division by 1000 converts the energy from joules to kilojoules, as the result is expressed in kJ/mol.

Q2: What are typical photon energy values?
A: Photon energies range from very small values for radio waves (10⁻¹⁰ kJ/mol) to large values for gamma rays (10⁶ kJ/mol).

Q3: Can I use wavelength instead of frequency?
A: Yes, frequency can be calculated from wavelength using \( f = \frac{c}{\lambda} \), where c is the speed of light.

Q4: Why use Avogadro's constant in this calculation?
A: Avogadro's constant converts from energy per photon to energy per mole of photons, which is more useful in chemical contexts.

Q5: What are the SI units for each parameter?
A: Planck's constant (J s), frequency (Hz), Avogadro's constant (mol⁻¹), and energy (kJ/mol).