Moderate

The energy of one mole of photons of radiation, whose frequency is 4×10 14 Hz, is ___________?

Correct answer: A. 159.6kJ

  • A. 159.6kJ
  • B. 135.5 KJ
  • C. 110.5 KJ
  • D. 80.4 KJ

Explanation

The energy of one photon is E = hν, so the energy of one mole is E = NAhν = (6.022 x 10^23 mol-1)(6.626 x 10^-34 J s)(4 x 10^14 s-1) = 1.596 x 10^5 J mol-1 = 159.6 kJ mol-1. Students may choose 80.4 kJ mol-1 by mishandling the frequency or losing a factor during conversion from joules to kilojoules.

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