JEE Main 2024 Chemistry question
The ionization energy of sodium in kJ mol⁻¹, if electromagnetic radiation of wavelength 242 nm is just sufficient to ionize sodium atom is .
Answer: 494
Solution
The energy per atom is E = hc/λ = (6.62 × 10⁻³⁴ × 3 × 10⁸)/(242 × 10⁻⁹) J. For 1 mole, E = /λ = 494.28 × 10³ J/mol ≈ 494 kJ/mol.