Ask Questions, Get Answers

Want to ask us a question? Click here
Browse Questions
0 votes

Iodine molecule dissociates into atoms after absorbing light of 4500$A^{\circ}$ .If one quantum of radiation is absorbed by each molecule,calculate the kinetic energy of iodine atoms (Bond energy of $I_2=240KJmol^{-1}$)

$\begin{array}{1 1}(a)\;0.216\times 10^{-19}J&(b)\;0.312\times 10^{-10}J\\(c)\;1.345\times 10^{-19}J&(d)\;0.114\times 10^{-14}J\end{array}$

Can you answer this question?

1 Answer

0 votes
Energy given to $I_2$ molecule $=\large\frac{hc}{\lambda}$
$\Rightarrow \large\frac{6.626\times 10^{-34}\times 3\times 10^8}{4500\times 10^{-10}}$
$\Rightarrow 4.417\times 10^{-19}J$
Energy used for breaking up of $I_2$ molecule=$\large\frac{2.4\times 10^3}{6.023\times 10^{23}}$
$\Rightarrow 3.984\times 10^{-19}J$
Energy used in importing kinetic energy to two I atoms
$\Rightarrow [4.417-3.984]\times 10^{-19}J$
Kinetic energy/iodine atom =$[(4.417-3.984)/2]\times 10^{-19}$
$\Rightarrow 0.216\times 10^{-19}J$
Hence (a) is the correct answer.
answered Jan 15, 2014 by sreemathi.v

Related questions

Ask Question
student study plans
JEE MAIN, CBSE, AIPMT Mobile and Tablet App
The ultimate mobile app to help you crack your examinations
Get the Android App