Enegry of one mole of photons of radiation whose frequency is `5xx10^(4)Hz` is_____`kJ mol^(-1)`.

Options

A. `288.54`
B. `478. 56`
C. `789.01`
D. `199.51`

Answer

D

Explanation

Enegry of one photon:
`E = hv = (6.26 xx 10^(-34)Js) (5xx10^(14)s^(-1))`
`= 3.313xx10^(-19)J`
Energy of one mole of photons, i.e., Avogardo's number of
photons `= (3.313xx10^(-19)J) (6.022xx10^(-23)mol^(-1))`
199.51 kJ mol^(-1)`