Question

Construct a Born-Haber cycle for the formation of the hypothetical compound NaCl2 where the sodium ion has a 2+ charge (the 1st and 2nd ionization energies for sodium are 496 KJ/mol and 4562 KJ/mol respectively).

(a) How large would the lattice energy need to be for the formation of NaCl2 to be exothermic

(b) If we were to estimate the lattice energy of NaCl2 to be roughly equal to that of MgCl2 (2326 KJ/mol), what value would you obtain for the standard enthalpy of formation (delta)H*f(formation), of NaCl2?

Answer 1