Which of the following statements are correct about `SF_(4)`?

Options

A. It is prepared by reacting sulphur directly with flurine
B. sulphur tetrafluoride hydrolysed by water to give `SO_(2)` and HF
C. `SF_(4)` has a square planar shape with S having two lone pair of electrons
D. S-atom has a expanded octet

Answer

To determine which statements about SF₄ (sulfur tetrafluoride) are correct, we will analyze each statement step by step.

### Step 1: Preparation of SF₄
**Statement:** SF₄ is prepared by reacting sulfur directly with fluorine.

**Analysis:** This statement is incorrect. SF₄ is not prepared by the direct reaction of sulfur and fluorine. Instead, it is synthesized by the reaction of sulfur dichloride (SCl₂) with sodium fluoride (NaF). The balanced reaction is:
\[ 3 \, \text{SCl}_2 + 4 \, \text{NaF} \rightarrow \text{SF}_4 + \text{S}_2\text{Cl}_2 + 4 \, \text{NaCl} \]
Thus, this statement is **false**.

### Step 2: Hydrolysis of SF₄
**Statement:** SF₄ hydrolyzes by water to give SO₂ and HF.

**Analysis:** This statement is correct. When SF₄ reacts with water, it hydrolyzes to produce sulfur dioxide (SO₂) and hydrofluoric acid (HF). The reaction can be represented as:
\[ \text{SF}_4 + 2 \, \text{H}_2\text{O} \rightarrow \text{SO}_2 + 4 \, \text{HF} \]
Thus, this statement is **true**.

### Step 3: Shape and Hybridization of SF₄
**Statement:** SF₄ has a square planar shape with sulfur having two lone pairs of electrons.

**Analysis:** This statement is incorrect. To determine the shape of SF₄, we can calculate its hybridization. Sulfur has 6 valence electrons, and there are 4 fluorine atoms (monovalent) attached to it. Using the formula:
\[ \text{Hybridization} = \frac{(V + M)}{2} \]
Where \( V \) is the number of valence electrons and \( M \) is the number of monovalent atoms:
\[ \text{Hybridization} = \frac{(6 + 4)}{2} = 5 \]
This indicates that sulfur is sp³d hybridized. With 4 bond pairs and 1 lone pair, the molecular geometry is trigonal bipyramidal with a seesaw shape, not square planar. Therefore, this statement is **false**.

### Step 4: Expanded Octet of Sulfur
**Statement:** The sulfur atom has an expanded octet.

**Analysis:** This statement is correct. In SF₄, sulfur forms 4 bonds with fluorine and has 1 lone pair, resulting in a total of 10 electrons around the sulfur atom. This exceeds the octet rule, indicating that sulfur has an expanded octet. Thus, this statement is **true**.

### Conclusion
The correct statements about SF₄ are:
- Statement 2: SF₄ hydrolyzes by water to give SO₂ and HF (True).
- Statement 4: The sulfur atom has an expanded octet (True).

### Final Answer
The correct statements are **2 and 4**.