The given question is incomplete. The complete question is :
It takes 151 kJ/mol to break an iodine-iodine single bond. Calculate the maximum wavelength of light for which an iodine-iodine single bond could be broken by absorbing a single photon. Be sure your answer has the correct number of significant digits.
Answer: 793 nm
Explanation:
The relation between energy and wavelength of light is given by Planck's equation, which is:

where,
E = energy of the light = 151 kJ= 151000 J (1kJ=1000J)
N= moles = 1 = 
h = Planck's constant = 
c = speed of light = 
= wavelength of light = ?
Putting in the values:


Thus the maximum wavelength of light for which an iodine-iodine single bond could be broken by absorbing a single photon is 793 nm
You must first calculate the total weight of 1 mole of the substance. You do this by finding the molar weights on the periodic table of each of the elements in the compound:

So now we take the amount of each element that is given in the compound and divide it by the total mass of the compound:
Carbon: 96.08g

Carbon = 49.48%
Nitrogen: 56.028g

Nitrogen = 28.85%
Oxygen: 31.998g

Oxygen = 16.48%
- The reaction in which we can't take back the product to reactant form .Or in simple words the reaction which is irreversible is called chemical reaction
Example:-
We cannot pull back the reaction to get wax back .
Yes because look in the book dh
Okay thanks for reminding me