An iodine molecule dissociates into atom after absorbing light of wavelength `4500`Å. If quantum of radiation is absorbed by each molecule calculate the kinetic energy of iodine (Bond energy of `I_(2)` is `240`` kJ mol^(-1))`

Answer

`2.186xx10^(-20)`Joules

Explanation

Energy given to `l_(2)` molecule
`=(hc)/(lambda)=(6.626xx10^(-34)xx3xx10^(8))/(4500xx10^(-10))=4.417xx10^(-19)J`
Also energy used for breaking up of `l_(2)` molecule `=(240xx10^(3))/(6.023xx10^(23))=3.984xx10^(-19)J`
`Therefore` Energy used in imparting kinetic energy to two 1 atoms `=[4.417-3.984]xx10^(-19)J`
`therefore K.E.//"idodine atom" [(4.417-3.984)//2]xx10^(-19)`
`=0.216xx10^(-19)J`