One of the spectral lines in the emission spectrum of mercury has a wavelength of
6.234 x 10–7 m. How much energy is emitted if 1.00 mole of mercury atoms emits light of 6.234 x 10–7 m? Express your answer in kJ/mol.

I have no idea how to even begin this.. please help!

Question

One of the spectral lines in the emission spectrum of mercury has a wavelength of
	6.234 x 10–7 m. How much energy is emitted if 1.00 mole of mercury atoms emits light 	of 6.234 x 10–7 m? Express your answer in kJ/mol.

I have no idea how to even begin this.. please help!

aaronq · Answer

plancks equation gives the energy for 1 photon of a given wavelength/frequency

$$E=h*\frac{ c }{ \lambda }=h*\nu$$
h= planck's constant,  6.626 × 10^-34  J/ s
lambda = wavelength (in meters)
c= speed of light, 2.9978 x10^8 m/s
v (nu)= frequency  (in 1/s (Hertz))  <- you don't need this for the question but i'm mentioning it for completion

once you find the energy of ONE photon, multiply by avogadros number to see how much energy one mole of photons gives.

you'll end up now with units, J/mol, they ask for kJ/mol,

so divide by 1000 to go from J -> kJ