Question

Iodine molecule dissociates into atoms after absorbing light of 4500A∘A∘.If one quantum of radiation is absorbed by each molecule,calculate the kinetic energy of iodine atoms (Bond energy of I2=240KJmol−1

Answer 1

Energy given to _{Iodine molecule = hc/λ}

= (6.62 × 10^-34 × 3 × 10^8) ÷ 4500× 10^-10

=4.417 × 10^-19 J

also, energy used for braking up iodine molecule = (240 × 10^3 )÷ (6.023 × 10 ^23) =3.984× 10^-19 J

(bcoz B.E. is given in per mole and we have to find out per molecule)

Energy used in imperting Kinetic energy to two I atoms = [4.417 -3.984] × 10 ^-19 J

so K.E per iodine atom = [4.417-3.984/2] × 10^-19

= .216 × 10^-19 J