`1 mol` of photons each of frequency `250s^(-1)` would have approximately a total enegry of

Options

A. `1 MeV`
B. `1 erg`
C. `1 J`
D. `1 eV`

Answer

B

Explanation

The enegry of one photon is given by
`E = hv`
Thus, the enegry of one mole of photons is obtained by multiplying the above relation by Avogadro's constant:
Total energy `= hVN_(0)`
`=(6.6xx10^(-34)Js)(250s^(-1))(6.02xx10^(-23)mol^(-1))`
`= 9933 xx 10^(-11)J`
`= 0.9933 xx 10^(-7)J`
`= 0.9933 erg (10^(-7)J = 1erg)`
`~~1 erg`