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Calculate energy from frequency?
I need to know how to calculate energy from frequency. I am using the equation energy = plank's constant*frequency. I know the answer should be 1.2*10^2 KJ/mol but I'm getting the wrong answer, I think I must be doing something wrong with the units. Frequency = 3*10^14 Hz and Planck's constant being 6.26*10^-34 J.s. So I do Energy =3*10^14 * 6.626*10^-34 and get the answer 1.9878*10^-19. What am I doing wrong?
3 Answers
- SS4Lv 78 years agoFavorite Answer
You are calculating the energy of a single photon but the answer is in terms of KJ/mol - it wants to know the energy a mole of photons would have.
Multiply by the Avogadro constant to get the answer 1.2*10^2 KJ/mol
- 8 years ago
answer is in KJ/mol.
you are solving for J.
so you need to multiply by 10*-3 and divide by the number of moles of whatever it is.
Either you need to re-read the question or verify that value is actually the answer.
