H2 Chemistry 7 - Chemical Energetics: Born-Haber Cycle for NaCl

What you will learn

• Builds a Born-Haber cycle with formation enthalpy -411, atomisation of Na +107, IE1 of Na +496, atomisation of Cl +122, and electron affinity of Cl -349 kJ/mol.
• Applies Hess' law: the formation enthalpy equals the sum of the indirect-route steps including the lattice energy.
• Solves for lattice energy of NaCl = -787 kJ/mol; the large negative value reflects strong electrostatic attraction between Na+ and Cl-.