Bond dissociation on energy of Br2 is 200 kJ/mole. The longest wavelength of photon that can breakthis bond would be

To find the longest wavelength of photon that can break this bond, we need to use the equation for the energy of a photon, which is E = hc/λ, where E is the energy, h is Planck's constant, c is the speed of light, and λ is the wavelength.

Step 1: Convert the bond dissociation energy from kJ/mole to J/photon.

1 mole of photons is Avogadro's number (6.022 x 10^23 photons).

So, 200 kJ/mole = 200,000 J/mole = 200,000 J / 6.022 x 10^23 photons = 3.32 x 10^-19 J/photon.

Step 2: Substitute the values into the equation E = hc/λ.

We know that h = 6.626 x 10^-34 J.s and c = 3.00 x 10^8 m/s.

So, 3.32 x 10^-19 J = (6.626 x 10^-34 J.s)(3.00 x 10^8 m/s) / λ.

Step 3: Solve for λ.

λ = (6.626 x 10^-34 J.s)(3.00 x 10^8 m/s) / 3.32 x 10^-19 J = 5.99 x 10^-7 m or 599 nm.

So, the longest wavelength of photon that can break this bond is approximately 599 nm.