1. What is Lattice Energy?

Lattice Energy (LE) is the energy required to completely separate one mole of a solid ionic compound into gaseous ions. It's a measure of the strength of the forces between ions in an ionic solid.

2. How Does the Calculator Work?

The calculator uses the simplified lattice energy equation:

Where:

• \( z^+ \) — Charge of the cation (dimensionless)
• \( z^- \) — Charge of the anion (dimensionless)
• \( r^+ \) — Radius of the cation (pm)
• \( r^- \) — Radius of the anion (pm)

Explanation: The equation shows that lattice energy increases with higher ion charges and decreases with larger ion sizes.

3. Importance of Lattice Energy

Details: Lattice energy helps predict solubility, melting points, and stability of ionic compounds. Higher lattice energy typically means higher melting points and lower solubility.

4. Using the Calculator

Tips: Enter ion charges as absolute values (e.g., 1 for Na⁺, 2 for Mg²⁺). Enter ionic radii in picometers (pm). All values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: What are typical lattice energy values?
A: Values typically range from 700 kJ/mol (e.g., NaCl) to 4000 kJ/mol (e.g., MgO) for common ionic compounds.

Q2: Why is the constant 1023 used?
A: This constant incorporates various physical constants and unit conversions to give results in kJ/mol when radii are in picometers.

Q3: What are limitations of this equation?
A: This is a simplified model. More accurate calculations consider crystal structure and additional electrostatic interactions.

Q4: How does lattice energy relate to solubility?
A: Generally, higher lattice energy means lower solubility, as more energy is needed to break the ionic bonds.

Q5: Can this be used for all ionic compounds?
A: It works best for simple binary compounds. Complex ions or compounds with significant covalent character may require more sophisticated models.