# Problem: A mole of red photons of wavelength 725 nm has kj of _____.

###### FREE Expert Solution

We’re being asked how many kj are being emitted by a 1 mole red light with 725 nm of wavelength.

Recall that the energy of a photon (E) is given by:

where:

h = Planck’s constant (6.626 × 10–34 J • s)

v = frequency (in s–1)

Also, recall that the frequency (v) and wavelength (λ) are related:

where:

c = speed of light (3.0 × 108 m/s)

90% (186 ratings) ###### Problem Details

A mole of red photons of wavelength 725 nm has kj of _____.

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