Question

What is the wavelength, in nm, of radiation that has an energy content of 1.0 * 10³ Kj/mol? In which region of the electromagnetic spectrum in this radiation found?

Answer 1

we have:

Energy of 1 mol = 1.0*10^3 KJ/mol

= 1.0*10^6 J/mol

Find energy of 1 photon first

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

= 1*10^6/(6.022*10^23)

= 1.661*10^-18 J

This is energy of 1 photon

we have below equation to be used:

Energy = Planck constant*speed of light/wavelength

1.661*10^-18J =(6.626*10^-34 J.s)*(3.0*10^8 m/s)/lambda

lambda = 1.197*10^-7 m

lambda = 120 nm

This is in ultraviolet region

120 nm

ultraviolet region