Question

Photons with a wavelength of 353 nm have just enough energy to rupture the C—Cl bond in CF3Cl. What is the C—Cl bond dissociation energy?

Answer 1

wavelength = 353 nm = 3.53*10^-7 m

Find energy of 1 photon first

we have below equation to be used:

Energy = Planck constant*speed of light/wavelength

=(6.626*10^-34 J.s)*(3.0*10^8 m/s)/(3.53*10^-7 m)

= 5.631*10^-19 J

This is energy of 1 photon

Energy of 1 mol = energy of 1 photon * Avogadro's number

= 5.631*10^-19*6.022*10^23 J/mol

= 3.391*10^5 J/mol

= 3.39*10^2 KJ/mol

Answer: 3.39*10^2 KJ/mol