BRAINCAKEBorn-Haber Cycles
A Born-Haber cycle is a type of Hess's Law energy cycle. Born-Haber cycles allow the enthalpy changes which cannot be measured directly to be calculated from other enthalpy changes. Elements in their standard state start the cycle on the bottom line. The next step is to add the enthalpy of formation. Arrows going downwards signify exothermic reactions. Arrows going upwards signify endothermic reactions. Each of the elements are then atomised in turn. This can be done in any order. Electrons are removed from the metal to make it into a positive gaseous ion. Electrons are added to the non-metal to make it a negative gaseous ion. The ions bond to form an ionic lattice.
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Key terms in this lesson
- hess's law
- The enthalpy change of a reaction is the same regardless of the route taken, provided the initial and final conditions are identical.
- lattice enthalpy
- The enthalpy change when one mole of an ionic lattice is formed from its constituent ions in the gaseous state, under standard conditions.
More in Lattice Enthalpy
- The Standard Enthalpy Change of Atomisation
- First Ionisation Energy
- First Electron Affinity
- First Electron Affinity
- Born-Haber Cycle for Sodium Oxide
- Born-Haber Cycle for Calcium Chloride
- Enthalpy Change of Hydration
- Enthalpy Change of Solution
All 10 lessons in Lattice Enthalpy · All Edexcel A-level Chemistry topics