Question

Use data from Table 3.3 to give an upper bound on thewavelengths of light that are capable of dissociating a molecule of ICl.

Short answer

The wavelength of light that is capable of dissociating a molecule of ICI is $9.55\times {10}^{-28}m$

Step-by-step solution

Step 1:Energy of light

The energy of light (E) can be evaluated from the known value of wavelength represented as$\mathbf{\lambda }$measured in meters. The energy is commonly measured in electron volt or in Joule.

Given information

The given data has values as follows:

• h =$6.626\times {10}^{-34}\text{Js}$ (Planck’s constant)

• c =$\text{2.99}\times {\text{10}}^{\text{8}}{\text{ms}}^{\text{-1}}$ (Speed of light)

• E = 208 kJ mol^-1(Bond dissociation energy of Cl-I bond)

Wavelength of light for dissociating molecule of ICI

From table 3.3, the bond dissociation energy of a typical Cl-I bond is approximately 208 kJ/mol.

The energy of radiation is related to its wavelength as given by the equation.

$\begin{array}{c}\text{E=}\frac{\text{hc}}{\text{λ}}\\ \text{or,λ=}\frac{\text{hc}}{\text{E}}\end{array}$

The known values are substituted.

$\begin{array}{c}\text{λ}=\frac{6.626\times {10}^{34}\times 2.9987\times {10}^8}{208}\\ =9.55\times {10}^{-28}m\end{array}$

Thus, the wavelength of light that are capable of dissociating a molecule of ICI is $9.55\times {10}^{-28}m$