I can't figure this problem out, despite using E = hc/lambda...
The first ionization energy for potassium in the vapor state is 418.8 kJ/mol. Determine the longest wavelength that could be used to ionize an atom of potassium.
I can't figure this problem out, despite using E = hc/lambda...
The first ionization energy for potassium in the vapor state is 418.8 kJ/mol. Determine the longest wavelength that could be used to ionize an atom of potassium.
$\displaystyle E = \dfrac{hc}{\lambda}$ only works for individual molecules. You need to find a scale factor between moles and molecules (think Avogadro) and watch the units, E in that equation is in joules whereas your value is in kJ
edit: I get an answer of 285.6nm