The basicity of the acid produced from the central atom in the hydrolysis of `AsCl_3` is

Options

A. 1
B. 2
C. 3
D. 4

Answer

To determine the basicity of the acid produced from the central atom in the hydrolysis of arsenic chloride (AsCl₃), we will follow these steps:

### Step 1: Understand Hydrolysis
Hydrolysis is the reaction of a substance with water. In the case of AsCl₃, it reacts with water to form an acid and hydrochloric acid (HCl).

### Step 2: Write the Hydrolysis Reaction
The hydrolysis of arsenic chloride can be represented as:
\[ \text{AsCl}_3 + 3 \text{H}_2\text{O} \rightarrow \text{H}_3\text{AsO}_3 + 3 \text{HCl} \]
In this reaction, arsenic trichloride reacts with water to produce arsenous acid (H₃AsO₃) and hydrochloric acid.

### Step 3: Identify the Acid
The acid produced from the central atom (arsenic) in this reaction is arsenous acid (H₃AsO₃).

### Step 4: Determine Basicity
Basicity refers to the number of hydroxide ions (OH⁻) that can be produced by the acid. In the case of H₃AsO₃, it has three hydrogen atoms that can dissociate to release three hydroxide ions:
\[ \text{H}_3\text{AsO}_3 \rightarrow \text{H}^+ + \text{H}_2\text{AsO}_3^- \]
\[ \text{H}_2\text{AsO}_3^- \rightarrow \text{H}^+ + \text{HAsO}_3^{2-} \]
\[ \text{HAsO}_3^{2-} \rightarrow \text{H}^+ + \text{AsO}_3^{3-} \]
Thus, the basicity of H₃AsO₃ is 3, as it can produce three hydroxide ions.

### Step 5: Conclusion
Therefore, the basicity of the acid produced from the central atom in the hydrolysis of AsCl₃ is **3**.