A research team studying the diatomic molecule B₂ obtains the following information from its potential-energy curve. The radial coordinate r is in nanometres, and the energy axis is in electronvolts (eV) per molecule. Zero energy corresponds to infinite separation.
• Minimum PE = –4.2 eV at r = 0.124 nm
• PE at r = 0.090 nm is –1.8 eV
• PE at r = 0.220 nm is –0.40 eV
(a) Determine the equilibrium bond length of B₂.
(b) Convert the bond energy to kJ·mol⁻¹.
(c) Calculate the energy, in kJ·mol⁻¹, required to compress one B₂ molecule from the equilibrium distance to 0.090 nm.
(d) A different bond has its potential-energy minimum at –2.1 eV. Using quantitative reasoning, explain whether the B₂ bond is relatively strong or weak compared with that bond.