Question

The IE1, for iodine, is 1009 kJ/mol. Calculate the wavelength (in nm) of electromagnetic energy need to ionize an iodine atom. 118.6 743.2 488.3 1042

Answer 1

118.6nm

Step-by-step explanation:

It is possible to calculate wavelength of any energetic process (As an ionization) using:

E = hc / λ (1)

Where E is Energy, h is Planck constant (6.626x10⁻³⁴Js), c speed of light (3x10⁸ms⁻¹) and λ is wavelength In meters.

As the energy to ionize 1 mole of iodine is 1009kJ, one atom requires:

(1009kJ / mol) ₓ (1mol / 6.022x10²³ atoms) = 1.6755x10⁻²¹kJ / atom. = 1.6755x10⁻¹⁸J

Replacing in (1):

λ = hc / E

λ = 6.626x10⁻³⁴Js*3x10⁸ms⁻¹ / 1.6755x10⁻¹⁸J

λ = 1.186x10⁻⁷m

As 1m = 1x10⁹nm:

1.186x10⁻⁷m ₓ (1x10⁹nm / 1m) =

118.6nm