Chemistry Frequency

Question

A local FM radio station broadcasts at an energy of 6.29 x 10^-29 kJ/photon. (1MHz = 10^6 s -1) Calculate the frequency at which it is broadcasting.

Frequency = ... MHz

Answer 1

One equation that relates frequency to energy is E = hν

E = energy per photon = 6.29x10^-29 kJ/photon

h = Planks constants = 6.626x10^-34 Js

v = frequency in s^-1 (Hz)

Before using this equation, we should get all of our units to agree, so we'll change E from kJ/photon to J/photon. 6.29x10^-29 kJ/photon x 1000 J / kJ = 6.29x10^-26 J/photon

Plugging into the equation and solving for v, we have...

v = E/h = 6.29x10^-26 J / 6.626x10^-34 Js

v = 94929067 s^-1 = 94929067 = 9.493x10⁷ Hz

9.493x10⁷ Hz x 1 MHz / 10⁶ Hz = 9.49 MHz