1. What is Lattice Energy?

Lattice energy (LE) is the energy released when gaseous ions combine to form one mole of a solid ionic compound. It's a measure of the strength of the ionic bonds in the compound.

2. The Born-Haber Cycle

The Born-Haber cycle is a thermodynamic cycle that calculates lattice energy from other measurable quantities:

Where:

• \( \Delta H_{sub} \) — Enthalpy of sublimation of the metal
• \( IE \) — Ionization energy of the metal
• \( \Delta H_{diss} \) — Enthalpy of dissociation of the non-metal
• \( EA \) — Electron affinity of the non-metal
• \( \Delta H_f \) — Enthalpy of formation of the ionic compound

Explanation: The cycle accounts for all energy changes involved in forming an ionic compound from its elements.

3. Importance of Lattice Energy

Details: Lattice energy helps predict compound stability, solubility, and melting points. It's crucial for understanding ionic compound properties and reactivity.

4. Using the Calculator

Tips: Enter all values in kJ/mol. The calculator sums the Born-Haber cycle components to determine lattice energy.

5. Frequently Asked Questions (FAQ)

Q1: Why is lattice energy usually negative?
A: Lattice energy is negative because energy is released when gaseous ions form a solid crystal lattice.

Q2: What factors affect lattice energy?
A: Lattice energy depends on ion charges (higher charges increase LE) and ion sizes (smaller ions increase LE).

Q3: How accurate is the Born-Haber cycle?
A: It provides good estimates but may have 5-10% error due to assumptions about perfect ionic behavior.

Q4: Can this be used for all ionic compounds?
A: It works best for simple ionic compounds with significant ionic character.

Q5: What's the relationship between LE and solubility?
A: Generally, higher lattice energy makes compounds less soluble as more energy is needed to break the lattice.