Question

Question #3b535

Answer 1

`2.16×10^-20J`

Explanation:

Energy given to each `"I"_2` molecule through one quantum of radiation`E=(hc)/λ`
where `h` is Planck's Constant, `c` is velocity of light in vacuum and `lambda` wave length of light quantum.

Inserting various values we get
`E=(6.626×10^-34×3×10^8)/(4500×10^-10)`
`⇒E=4.417×10^-19J`

We know that one mole of `"I"_2` molecule`=`Avogadro's number.
`:.`Energy used for breaking up of each `"I"_2` molecule`=(2.4×10^3)/(6.023×10^23)`
`=3.984×10^-19J`

Balance energy is used in imparting kinetic energy to two Iodine atoms`E_b=(4.417-3.984)×10^-19J`
Kinetic energy of each Iodine atom `E_b/2=(4.417−3.984)/2×10^-19`
`=2.16×10^-20J`