Please help solve!

Question

What is the energy (in J) of a mole of photons that have a wavelength of 517 nm? (h = 6.626 × 10⁻³⁴ J • s and c = 3.00 × 10⁸ m/s)

Answer 1

For this problem use the formula E_photon = hc

λ

h- is Planck's constant which is 6.626 x 10^-34 J*s

c- is speed of light which is 3.0 x 10⁸m/s

λ- is the wavelength

517 nm x 10^-9 m = 5.17 x 10^-7 m

1 nm

E_photon = ( 6.626 x 10^-34 J*s)(3.0 x 10⁸ m/s)

5.17 x 10^-7 m

E_photon = 3.84 x 10^-19 J/photon

Use Avogadro's number to cancel out the photons to find the Joules

3.84 x 10^-19 J/photon x 6.02 x 10²³ photons/mole x 1 mole = 2.31 x 10⁵ J