Answer:
493.02 nm is the longest wavelength of light that will produce free chlorine atoms in solution.
Explanation:
[tex]Cl_2(g)\rightarrow 2Cl(g)[/tex] ,ΔH = 242.8 kJ/mol
Energy required to break 1 mole of Cl-Cl bond = 242.8 kJ
Energy required to break 1 Cl-Cl bond = E
[tex]E = \frac{242800 J}{6.022\times 10^{23}}=4.032\times 10^{-19} J[/tex]
Energy related with the wavelength of light is given by Planck's equation:
[tex]E=\frac{hc}{\lambda }[/tex]
[tex]\lambda =\frac{hc}{E}[/tex]
[tex]=\frac{6.626\times 10^{-34} Js\times 3\times 10^8 m/s}{4.032\times 10^{-19} J}[/tex]
[tex]\lambda = 4.930\times 10^{-7} m = 493.02 nm[/tex]
[tex]1 m = 10^09 nm[/tex]
493.02 nm is the longest wavelength of light that will produce free chlorine atoms in solution.
