Answer:
The maximum wavelength of light that can dissociate diatomic chlorine into the monatomic chlorine form is 984 nm.
Explanation:
Given: ΔHf° value for atomic chlorine is +121.7 kJ/mol
1 Step
Converting kJ/mol into kJ (knowing that in 1 mol there is 6.023*10^23 molecules)
ΔHf° in kJ = 121.7 kJ/mol* 1 mole / 6.023*10^23
ΔHf° = 2.02*10^-22 kJ
ΔHf° = E = 2.02*10^-19 J
2 Step
Converting ΔHf° to a wavelength:
knowing the E = h*C/У
h = 6.626 x 10^-34 J·s
C = 3.00 x 10^8 m/s
У = h*C/E = (6.63 x 10^-34 J·s)(3.00 x 108 m/s) / 2.02*10^-19 J
У = 9.84*10^-7 m = 984 nm
3 Step (What type of radiation?)
UV-A wavelength range = 315 nm to 400 nm
UV-B wavelength range = 280 nm to 315 nm
UV-C wavelength range = 100 nm to 280 nm
This wavelength is not corresponding to any of the wavelength range (UV-A, UV-B, UV-C).
