Q. $I_{2}$ molecule dissociates into atoms after absorbing light of 4500 $A{^\circ}$. If one quantum of energy is absorbed by each molecule, the KE of iodine atoms will be (BE of $I_{2} = 240$ kJ/mol)
A) 240$\times 10^{- 19}$ J
B) 0.216$\times 10^{- 19}$ J
C) 2.16$\times 10^{- 19}$ J
D) 2.40$\times 10^{- 19}$ J
Explanation
(b)
Step 1 Calculate energy given to $I_{2}$ molecule by $\frac{hc}{\lambda}$
Step 2 Calculate energy used to break $I_{2}$ molecule. The difference in above two energies will be the KE of two I atoms
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.