Chlorofluorocarbons (CFC's) are organic compounds that have been implicated in ozone depletion. When the CFC known as Freon 12 (CCl2F2) is exposed to UV radiation (wavelength in the range of 10 nm to 400 nm, a bit shorter than visible light), a chlorine atom breaks off from the rest of the molecule. Prove that this is possible by calculating the maximum wavelength (in meters) capable of breaking the C-Cl bond.

Question

Chlorofluorocarbons (CFC's) are organic compounds that have been implicated in ozone depletion. When the CFC known as Freon 12 (CCl2F2) is exposed to UV radiation (wavelength in the range of 10 nm to 400 nm, a bit shorter than visible light), a chlorine atom breaks off from the rest of the molecule. Prove that this is possible by calculating the maximum wavelength (in meters) capable of breaking the C-Cl bond.

Answer 1

Look up the C-Cl bond energy in joules, then E = hc/wavelength and solve for wavelength.

Answer 2

To calculate the maximum wavelength capable of breaking the C-Cl bond in CFC (Freon 12), we need to use the concept of the bond dissociation energy and convert it into energy units corresponding to a specific wavelength.

Here's how you can calculate it:

Step 1: Find the bond dissociation energy of the C-Cl bond.
The bond dissociation energy represents the energy required to break apart a specific bond. In this case, we need to find the bond dissociation energy for the C-Cl bond. According to literature, the bond dissociation energy for C-Cl is approximately 327 kilojoules per mole (kJ/mol).

Step 2: Convert bond dissociation energy to energy per photon.
To convert the bond dissociation energy to energy per photon, we can use the equation:
E = hc/λ
where:
- E is the energy per photon,
- h is Planck's constant (6.626 x 10^-34 J·s),
- c is the speed of light (3.0 x 10^8 m/s),
- λ is the wavelength of light.

We need to rearrange the equation to solve for λ:
λ = hc/E

Step 3: Calculate the maximum wavelength.
To calculate the maximum wavelength that can break the C-Cl bond, we need to calculate the energy per photon using the bond dissociation energy (E = 327 kJ/mol = 3.27 x 10^5 J/mol) and follow through with the equation from Step 2.

λ = (6.626 x 10^-34 J·s * 3.0 x 10^8 m/s) / (3.27 x 10^5 J/mol)

By substituting the values and performing the calculation, we can find the maximum wavelength capable of breaking the C-Cl bond.

Note: The calculation yields approximately 6.06 x 10^-8 meters or 60.6 nm as the maximum wavelength capable of breaking the C-Cl bond in Freon 12 (CCl2F2) when exposed to UV radiation.

Therefore, the maximum wavelength capable of breaking the C-Cl bond is determined to be around 60.6 nm.