How much energy (in J) is contained in 1.00 mole of 699 nm photons?

Answer 1

The energy of a photon can be calculated by the following formula: E = hc/λ

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

c is speed of light or 3 x 10⁸ m/s

λ is the wavelength given in this question, or 699 nm.

Plug all values into the formula:

E = hc/λ = (6.626 x 10^-34 J s) (3 x 10⁸ m/s)/ (699 x 10^-9m)

E = 2.84 x 10^-19 J for one photon

To calculate the energy for one mole of photons, 1 mole of photons is equal to 6.02 x 10²³ photons

Cancel like units:

(2.84 x 10^-19 J/photon) (6.02 x 10²³photons/mole) = 1.71 x 10⁵ J/mol (Answer)