Excess of `PCl_5` reacts with `conc. H_2 SO_4` gives

Options

A. Sulphuryl chloride
B. Sulphurous acid
C. Chlorosulphonic acid
D. Thionyl cloride

Explanation

To solve the question of what products are formed when excess PCl5 reacts with concentrated H2SO4, we can follow these steps:

### Step 1: Understand the Reactants
We have two reactants: phosphorus pentachloride (PCl5) and concentrated sulfuric acid (H2SO4).

### Step 2: Identify the Reaction
When PCl5 reacts with concentrated H2SO4, it is important to note that PCl5 is a chlorinating agent and can replace the hydroxyl (OH) groups in H2SO4 with chlorine atoms.

### Step 3: Write the Reaction
The reaction can be represented as:
\[ \text{H}_2\text{SO}_4 + 2 \text{PCl}_5 \rightarrow \text{SO}_2\text{Cl}_2 + \text{POCl}_3 + \text{HCl} \]
Here, sulfuryl chloride (SO2Cl2) is formed along with phosphorus oxychloride (POCl3) and hydrochloric acid (HCl).

### Step 4: Identify the Main Product
Among the products formed, the question asks for the primary product. The main product formed in this reaction is sulfuryl chloride (SO2Cl2).

### Step 5: Conclusion
Thus, the answer to the question is that the excess of PCl5 reacting with concentrated H2SO4 gives sulfuryl chloride (SO2Cl2).

### Final Answer
The correct answer is **sulfuryl chloride (SO2Cl2)**.

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