Wavelength for breaking a bond

[guiromero]

Mentor's Note: Post moved to homework forum from chemistry forum.

Hello,

I have a doubt in anexercise from MIT:
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Calculate the maximum wavelength, λ, of electromagnetic radiation capable of breaking the weakest bond in of AsClF42-.

Bond Energies (kJ/mol): As-As 180; F-F 160; Cl-Cl 240.

Enter the numerical value of λ in meters:
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This molecule has As-Cl and Cl-F bonds, but I don't know how to calculate these bonds energies from the given values. Does anynone know how to do that?

Thanks a lot.

 

[DrClaude]

Could there be a previous question with some additional information? Because the question cannot be answered with the data given.

 

[guiromero]

There's a previous question simliar to that, but I can't find the statement. However, I know the formulas are:

Energy (J) = [BE * 1000] / Avogador's number

Where:
BE: Bond energy (KJ/mol)

Wavelength (m) = (h * c) / Energy

Where:
h: Plancks' constant (m^2 * kg * s^-1)
c: Speed of light (m * s^-1)

In this case, BE should be the smallest value among the bond energies found in the molecule. I find that this molecule only has two types of bonds: As-Cl and Cl-F. However, I don't know how to calculate any of these bonds' energies from the data given (Bond energies of As-As 180; F-F 160; Cl-Cl 240).

I thought of taking the mean value of two given bond energies, for example :

Bond energy of As-Cl = (Bond energy of As-As + Bond energy of Cl-Cl) / 2

But this didn't work. Do you know how to do that?

 

[Mayhem]

Are the given bond energies dummy values? Because literature says As-As is around 380 kJ/mol.[1][2]

 

[guiromero]

Are the given bond energies dummy values? Because literature says As-As is around 380 kJ/mol.[1][2]

As they are different from the literature values, I suppose they are dummy. Thanks for your help.