Chemical Bonding #03//Lattice Energy,Born Haber cycle//Class 11, NEET, JEE STUDENTS

Lattice Energy and Born-Haber Cycle Lattice Energy Lattice energy () is the energy released when one mole of an ionic compound is formed from its gaseous ions. Alternatively, it can be defined as the energy required to break one mole of an ionic compound into its gaseous ions. Factors Affecting Lattice Energy 1. Charge of Ions: Higher the charge, stronger the attraction, and higher the lattice energy. Example: has higher lattice energy than . 2. Ionic Radius: Smaller the ion, stronger the attraction, and higher the lattice energy. Example: has higher lattice energy than . 3. Nature of Crystal Structure: More compact structures have higher lattice energy. Born-Haber Cycle Born-Haber cycle is a thermodynamic cycle used to calculate the lattice energy of ionic compounds using Hess’s Law. Steps in the Born-Haber Cycle (for NaCl as an example): 1. Sublimation Energy () Converts solid metal to gaseous atoms. 2. Bond Dissociation Energy () Breaks bonds in diatomic molecules to form individual atoms. 3. Ionization Energy () Removes an electron from a gaseous metal atom. 4. Electron Affinity () Adds an electron to a non-metal atom. 5. Lattice Energy () Formation of ionic solid from gaseous ions. Hess’s Law Equation: \Delta H_f = \Delta H_{sub} + \Delta H_{diss} + IE + EA + U_L Application in NEET & JEE Questions related to trends in lattice energy. Calculation-based problems on Born-Haber cycle. Conceptual problems on factors affecting lattice energy. Would you like some example problems or further explanations?