Question

4. Depending on temperature, RbCl can exist in either the rock-salt or caesium chloride structure. a) What is the coordination number of the cation and anion in each of these structures? b) In which of these structures will Rb have the larger apparent radius?

5. Calculate the lattice enthalpy for magnesium bromide using the Born-Haber cycle method, using the provided table. Process Enthalpies, ΔHɵ /(kJ mol-1 ) Sublimation of Mg(s) +148 Ionization of Mg(g) +2187 to Mg2+(g) Vaporization of Br2(l) +31 Dissociation of Br2(g) +193 Electron gain by Br(g) -331 Formation of MgBr2(s) -524