How much energy (in kj) do 3.0 moles of photons, all with a wavelength of 670 nm, contain? how much energy (in kj) do 3.0 moles of photons, all with a wavelength of 670 nm, contain? 360 kj 179 kj 536 kj 242 kj 412 kj?

1 mole of photons contain photons (Avogadro number). This means that 3.0 moles of photons contain
photons.

The wavelength of the light in the problem is , so the frequency is


The energy carried by a single photon is

where is the Planck constant, while f is the frequency. Since this is the energy carried by a single photon, the energy carried by 3.0 moles of photons will be the energy of the single photon multiplied by the total number of photons:

which corresponds to E=536 kJ.