For a K+ –Cl– ion pair, attractive and repulsive energies EA and ER , respectively, depend on the distance between the ions r, according to For these expressions, energies are expressed in electron volts per K+ –Cl– pair, and r is the distance in nanometers. The net energy EN is just the sum of the two expressions above. (a) Superimpose on a single plot EN, ER, and EA versus r up to 1.0 nm.
(b) On the basis of this plot, determine
(i) the equilibrium spacing r0 between the K+ and Cl– ions, and
(ii) the magnitude of the bonding energy E0 between the two ions.
(c) Mathematically determine the r0 and E0 values using the solutions to Problem 4 and compare these with the graphical results from part (b)