Answer:
energy = 391.902 kJ /mol
Explanation:
given data
wavelength = 305 nm = 305 Ă—[tex]10^{-9}[/tex] m
to find out
average energy
solution
we know speed of light is 3 Ă—[tex]10^{8}[/tex] m/s
so we find frequency here first by speed of light formyla
speed = wavelength Ă— frequency
3 Ă—[tex]10^{8}[/tex] Â = 305 Ă—[tex]10^{-9}[/tex] Ă— frequency
frequency = 9.8360 Ă—[tex]10^{14}[/tex] [tex]s^{-1}[/tex]
so energy is
energy = hf
here h = 6.62 Ă—[tex]10^{-34}[/tex] J-s
so
energy = Â 6.62 Ă—[tex]10^{-34}[/tex] Â Ă— 9.8360 Ă—[tex]10^{14}[/tex]
energy = 6.51 Ă—[tex]10^{-14}[/tex] J
so
energy = 6.51 Ă—[tex]10^{-14}[/tex] Â Ă— [tex]\frac{6.02*10^23}{1000}[/tex] kJ/mol
energy = 391.902 kJ /mol