Light Relationship

Question

What is the energy of 2.24 x 10^–3 moles of 2.13 nm X-ray photons? in kj

*two experts have got this wrong its tricky

Answer 1

E of one photon is hc/λ

Pay attention to units: (6.626 x 10^-31 J-s)(3.00 x 10⁸ m/s)/(2.13 x 10^-9m) = 9.332 x 10^-14 J/Photon

Multiply the moles times photons/mole times the J/photon and convert to kJ

(2.24 x 10^-3 moles)(6.02 x 10²³ phot/mole)(9.332 x 10^-14 J/phot)(1 kJ/1000J) = 126000 kJ

Please consider a tutor. Take care.