Halides of Be dissolve in organic solvent while of Ba do not

Options

A. High hydracation energy of Be halides
B. High lattice energy of barium halides
C. Large size of `Ba^(2+)`
D. Halides of Be are covvalent but that of Ba are ionic

Answer

### Step-by-Step Solution:

1. **Understanding the Compounds**:
- Beryllium halide (BeCl2) and Barium halide (BaCl2) are the two compounds in question.
- Beryllium (Be) is a small atom with a high ionization energy, while Barium (Ba) is a larger atom with a lower ionization energy.

2. **Nature of the Halides**:
- Beryllium halides (like BeCl2) are predominantly covalent due to the high ionization energy of beryllium. This means that BeCl2 does not fully dissociate into ions in solution, but rather forms covalent bonds.
- Barium halides (like BaCl2), on the other hand, are ionic because Barium has a lower ionization energy, allowing it to lose electrons easily and form Ba²⁺ ions.

3. **Solubility in Organic Solvents**:
- Covalent compounds (like BeCl2) tend to dissolve in organic solvents because they can interact favorably with the solvent molecules through dipole interactions or van der Waals forces.
- Ionic compounds (like BaCl2) do not dissolve well in organic solvents because they require a polar solvent (like water) to stabilize the ions formed upon dissociation.

4. **Conclusion**:
- Therefore, the reason why beryllium halides dissolve in organic solvents while barium halides do not is due to the covalent nature of beryllium halides compared to the ionic nature of barium halides.

### Final Answer:
Beryllium halides (like BeCl2) are covalent and dissolve in organic solvents, while barium halides (like BaCl2) are ionic and do not dissolve in organic solvents.