Structural formula for lewisite is

Options

A. `underset(underset(CHAsCl_(3))(||))(CHCl)`
B. `underset(underset(CHAsCl)(||))(CHCl)`
C. `underset(underset(CHAsCl_(2))(||))(CHCl)`
D. `underset(underset(CHAsCl_(2))(||))(CH_(2))`

Explanation

To determine the structural formula for lewisite, we will follow these steps:

### Step 1: Identify the Molecular Formula
The molecular formula of lewisite is given as C2H2AsCl3. This indicates that the compound contains:
- 2 Carbon (C) atoms
- 2 Hydrogen (H) atoms
- 1 Arsenic (As) atom
- 3 Chlorine (Cl) atoms

### Step 2: Determine the Basic Structure
Lewisite can be derived from a vinyl group (C=C) and an arsenic-containing group. The basic structure can be represented as:
- A carbon-carbon triple bond (C≡C) or double bond (C=C) is common in alkenes and alkynes.

### Step 3: Incorporate the Arsenic and Chlorine Atoms
The structural representation of lewisite can be built by adding the arsenic and chlorine atoms to the carbon skeleton. The structure can be represented as:
- CHCl=CH-AsCl2
This indicates that one carbon is bonded to a chlorine atom and the other carbon is double-bonded to the arsenic atom, which is also bonded to two chlorine atoms.

### Step 4: Draw the Structural Formula
The final structural formula for lewisite can be illustrated as follows:
```
Cl
|
H2C=C
|
As
/ \
Cl Cl
```
This structure shows the connectivity of the atoms in lewisite.

### Conclusion
The structural formula for lewisite is CHCl=CH-AsCl2.

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