Which of the following is least ionic ?

Options

A. `C_(2)H_(5) Cl`
B. `KCl`
C. `BaCl_(2)`
D. `C_(6)H_(5)N^(+)Cl^(-)`

Answer

To determine which of the given compounds is least ionic, we need to analyze the nature of the bonds in each compound. Here's a step-by-step solution:

### Step-by-Step Solution:

1. **Identify the Compounds**: The question refers to four compounds, which we need to analyze for their ionic character. The compounds mentioned are:
- C2H5Cl (Ethyl chloride)
- KCl (Potassium chloride)
- BaCl2 (Barium chloride)
- C6H5N + Cl- (Phenyl ammonium chloride)

2. **Analyze C2H5Cl**:
- C2H5Cl is composed of carbon (C), hydrogen (H), and chlorine (Cl).
- The bonds in C2H5Cl are primarily covalent due to the relatively small difference in electronegativity between C, H, and Cl.
- Since the bonds are covalent, C2H5Cl has a high covalent character and thus a low ionic character.

3. **Analyze KCl**:
- KCl is formed from potassium (K) and chlorine (Cl).
- The difference in electronegativity between K and Cl is significant, leading to the formation of K+ and Cl- ions.
- Therefore, KCl is an ionic compound.

4. **Analyze BaCl2**:
- BaCl2 consists of barium (Ba) and chlorine (Cl).
- Similar to KCl, the electronegativity difference between Ba and Cl is large, resulting in the formation of Ba^2+ and Cl- ions.
- Hence, BaCl2 is also an ionic compound.

5. **Analyze C6H5N + Cl-**:
- This compound consists of a phenyl group (C6H5) bonded to an ammonium ion (N) and a chloride ion (Cl-).
- The presence of Cl- indicates that this compound also has ionic character, as it dissociates into ions.

6. **Conclusion**:
- Among the four compounds analyzed, C2H5Cl has the highest covalent character and the least ionic character.
- Therefore, the compound that is least ionic is **C2H5Cl**.

### Final Answer:
**C2H5Cl is the least ionic among the given options.**