Question

Photochemical dissociation of oxygen result in the production of two oxygen atoms one in the ground state and in the excited state
`O_(2) overset(hv) to O + O^(6)`
The maximum wavelenght (1) neded for this is `17.4` nm .If the exchation energy `O rarr O^(6) is 3.15 xx 10^(-19) J` haw much energy in kJ `mol^(-1)` is neded for the dissociation of `1` and of oxygen into normal atomic is the ground state

Answer 1

Energy required per molecule in the process
`iO_(2) overset(hv) to O + O^(6) `may be gives as
`E = (hc)/(lambda) = (6.626 xx 10^(-16) xx 3 xx 10^(8))/(174 xx 10^(-9))`
`= 11.424 xx 10^(-19)`joule per molecule
Energy for `O rarr O^(6) is 3.15 xx 10^(-19) J`
This energy for `O_(2) rarr 20 `will be
`11.424 xx 10^(-19) - 3.15 xx 10^(-19)= 8.274 xx 10^(-19) J`
For one mole`= E xx N_(A) `(Avogadro number)
`= 8.247 xx 10^(-19) xx 6.023 xx 10^(23)`
`= 498.3 kJ mol ^(-1)`