Choose the correct order of lattice enthalpy in the following.

Options

A. `LiF gt NaCl gt NaF gt LiCl`
B. `LiF gt LiCl gt NaF gt NaCl`
C. `LiF gt NaF gt NaCl gt LiCl`
D. `LiCl gt LiF gt NaF gt NaCl`

Explanation

To determine the correct order of lattice enthalpy among the given compounds, we need to consider the factors that influence lattice energy. Lattice energy is the energy released when gaseous ions combine to form an ionic solid. The key factors affecting lattice energy are:

1. **Charge of the ions**: Higher charges lead to stronger electrostatic forces and thus higher lattice energy.
2. **Size of the ions**: Smaller ions can get closer together, which increases the electrostatic attraction and results in higher lattice energy.

### Step-by-Step Solution:

1. **Identify the Compounds**:
Let's assume the compounds in question are LiF, NaF, LiCl, and NaCl.

2. **Analyze the Cation Size**:
- Li⁺ is smaller than Na⁺.
- Therefore, compounds containing Li⁺ will generally have higher lattice energy compared to those with Na⁺.

3. **Analyze the Anion Size**:
- F⁻ is smaller than Cl⁻.
- Thus, compounds containing F⁻ will generally have higher lattice energy compared to those with Cl⁻.

4. **Compare Lattice Energies**:
- **LiF vs. NaF**: Since Li⁺ is smaller than Na⁺ and F⁻ is the same in both, LiF will have a higher lattice energy than NaF.
- **LiCl vs. NaCl**: Again, Li⁺ is smaller than Na⁺, but Cl⁻ is larger than F⁻. However, the difference in cation size will still favor LiCl over NaCl in terms of lattice energy.
- **LiF vs. LiCl**: LiF has a smaller anion (F⁻) compared to LiCl (Cl⁻), so LiF will have a higher lattice energy than LiCl.
- **NaF vs. NaCl**: NaF will have a higher lattice energy than NaCl for the same reason as above.

5. **Final Order of Lattice Enthalpy**:
Based on the above analysis, the correct order of lattice enthalpy from highest to lowest is:
- LiF > LiCl > NaF > NaCl

### Final Answer:
**LiF > LiCl > NaF > NaCl**