Choose the correct options :

Options

A. Nacl has greater lattice energy than MgO
B. Dipole moment of `Becl_(2)` is Zero above 1200 K temperature .
C. The bond angle in `OF_2` is lesser than `OC l_2`
D. The Be atom in `BeCl_2(s)` in `sp^3` hybridised

Explanation

To solve the given question, we need to evaluate each statement regarding the properties of the compounds NaCl, MgO, BeCl2, OF2, and OCl2. Let's analyze each statement step by step.

### Step-by-Step Solution:

1. **Statement 1: NaCl has greater lattice energy than MgO.**
- **Analysis:** Lattice energy is directly proportional to the charge of the ions. NaCl consists of Na⁺ (charge +1) and Cl⁻ (charge -1), while MgO consists of Mg²⁺ (charge +2) and O²⁻ (charge -2). Since MgO has ions with higher charges, it will have greater lattice energy than NaCl.
- **Conclusion:** This statement is **false**.

2. **Statement 2: The dipole moment of BeCl2 is 0 above 1200 Kelvin.**
- **Analysis:** Below 1200 K, BeCl2 exists as a dimer, but above this temperature, it exists as a linear molecule (BeCl2). In a linear molecule, the dipole moments of the two Be-Cl bonds cancel each other out due to their symmetrical arrangement, resulting in a net dipole moment of zero.
- **Conclusion:** This statement is **true**.

3. **Statement 3: The bond angle in OF2 is lesser than OCl2.**
- **Analysis:** The bond angle is inversely related to the electronegativity of the substituents. Fluorine is more electronegative than chlorine, which means that the bond angle in OF2 will be smaller than that in OCl2 due to the higher electronegativity of fluorine attracting electron density away from the central oxygen atom.
- **Conclusion:** This statement is **true**.

4. **Statement 4: The Be atom in BeCl2 solid is sp³ hybridized.**
- **Analysis:** In the solid state, BeCl2 forms a structure where beryllium is surrounded by four chlorine atoms, leading to the formation of four bonds. This indicates that the hybridization of beryllium in this structure is sp³.
- **Conclusion:** This statement is **true**.

### Final Conclusion:
Based on the analysis:
- Statement 1 is false.
- Statements 2, 3, and 4 are true.

Thus, the correct options are **2, 3, and 4**.