Question

Q. 11 Calculate the wavelength of the radiation that would cause photo dissociation of chlorine molecule if the $ext{Cl}- ext{Cl}$ bond energy is $241 ext{KJ} / ext{mol}$.

• A. $594\, nm$
• B. $640\, nm$
• C. $700\, nm$
• D. $494\, nm$

Answer 1

Answer: (D)

$494\, nm$

Answer 2

Energy required for $1\, Cl_2$ molecule $= \frac{242\times10^{3}}{N_{A}}$ Joules. This energy is contained in photon of wavelength $?\lambda?$. $\frac{hc}{\lambda} = E \Rightarrow \frac{6.626\times 10^{-34}\times 3\times 10^{8}}{\lambda} = \frac{242\times 10^{3}}{6.022\times 10^{23}}$ $\lambda = 4947\,? \approx 494\, nm$