Finding binding energy from equilibrium bond length

[llabesab16]

[b]1. The equilibrium bond length of the He dimer is 2.97 angstroms. What is the binding energy in kJ/mol for this dimer? Would be dimer be stable at room temperature T= 300K (Hint: compare the binding energy to kT)



[b]2. interaction potential for the dimer:

V(r) = (B/r^13)-(C/r^6), where B= 9.29 x 10^4 kJ(angstrom^13)(mol^-1) and C= 97.7 kJ (angstrom^6)(mol^-1)




[b]3. I didn't know what to do. My guess was to plug the equilibrium bond length into the interaction potential equation, but this gave me a negative answer. I figured that my answer couldn't be negative if I had to compare the binding energy to kT. Any help would be greatly appreciated.

Thanks!

[Borek]

Perhaps negative binding energy tells you something about stability?

--
chemical calculators (http://www.chembuddy.com) - buffer calculator (http://www.chembuddy.com/?left=Buffer-Maker&right=buffer-calculator), concentration calculator (http://www.chembuddy.com/?left=CASC&right=concentration_and_solution_calculator)
www.titrations.info (http://www.titrations.info) - all about titration (http://www.titrations.info) methods