Question

It takes

242./kJ mol
to break a chlorine-chlorine single bond. Calculate the maximum wavelength of light for which a chlorine-chlorine single bond could be broken by absorbing a single photon

Answer 1

The maximum wavelength that can break a Cl-Cl bond is 494 nm.

Energy to break 1 Cl-Cl bond

Energy = (242 kJ/1 mol) × (1000 J/1 kJ) × (1 mol/6.022 × 10²³ bonds)

= 4.019 × 10⁻¹⁹ J/bond

Wavelength of photon

E = hf = (hc)/λ

λ = (hc)/E = (6.626 × 10⁻³⁴ J × 2.998 × 10⁸ m·s⁻¹)/(4.019 × 10⁻¹⁹ J) = 4.94 × 10⁻⁷ m = 494 nm