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What is the energy for a mole of photons of light that have a wavelength of 655 nm?.

User Michael Villeneuve
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1 Answer

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Answer:

1.82 x 10^5 J

Step-by-step explanation:

The energy of a mole of photons of the light is 1.82 × 105 J.

The wavelength is given in nanometers but needs to be converted to meters.

655 nanometers times 1 × 10-9 meters over 1 nanometer equals 6.55 × 10-7 meters

Use the wavelength in meters, Planck’s constant, and the speed of light to find the wavelength.

Energy equals Planck’s constant times the speed of light over wavelength

Energy equals 6.626 × 10-34 joules-seconds times 3.00 × 108 meters per second divided by 6.55 × 10-7 meters

E = 3.03 x 10-19 J

The calculated energy is for a single photon. Use the energy per photon and Avogadro’s number to find the energy of a mole of photons.

3.03 × 10-19 joules over photon times 6.022 × 1023 photons over mole equals

1.82 × 105 joules per mole

User Pierreemmanuel
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