Question

for a light of wavelength 400 nm calculate frequency wavenumber energy per Quantum and per mole.
please guys solved it detailedly

Answer 1

frequency (f)
= velocity of light / wavelength

so

f = 3 × 10^8/ 400× 10^-9

= 7.5 × 10^15 Hz

and

energy of photon
= h × f

here is plank constant
and

h = 6.63×10^-34 js

so energy
=6.63×10^-34×7.5×10^15

= 49.725×10^-19 j

and

per mole energy = 49.725×10^-19×6.62×10^23

= 329.1795 × 10^4 j


## hope it can help you $$