Experimentally the ionization energy of hydrogen is 1312.2 kJ / mol. What would be the wavelength (nm) of a photon with enough energy to ionize one atom of hydrogen?

Question

They give the equation E=hcR but those are all known constant values and none include mols so I'm very confused.
Thanks!

Answer 1

divide the energy by 2*avagrado's number, the number of atoms in a mole of H2

Then, use Planck's equation to find the wavelength.

Answer 2

Wait, what's planck's equation??

Answer 3

Energy= Planck's constant* speedlight/wavelength

Answer 4

Ok that's what I thought!
So my answer should be 182.45 nm, yes?

Answer 5

Because I had to convert kJ to J
So I did:
1312200/2(6.022x10^23)
6.626x10^-34(3x10^8)/ans
and then that answerx 10^9 to convert to nm
Where did I go wrong because that answer wasn't correct =(

Answer 6

Here is a site that may be interesting to you and may shed some light on your problem.
http://en.wikipedia.org/wiki/Molar_ionization_energies_of_the_elements

This shows ionization energy = 1312 kJ/mol H ATOMS.