The substance employed as a tear gas is

Options

A. `COCl_2`
B. `CH_3Cl`
C. `CH_3COCl`
D. `"CC"l_3NO_2`

Answer

To solve the question regarding the substance employed as a tear gas, we will follow these steps:

### Step 1: Identify the options given
The options provided are:
1. COCl2
2. CH3Cl
3. CH3COCl
4. CCl3NO2

### Step 2: Recall the common tear gas substances
Tear gases are chemical compounds that can cause irritation to the eyes, leading to tears. A well-known tear gas is chloropicrin.

### Step 3: Determine the chemical formula of chloropicrin
Chloropicrin is chemically represented as CCl3NO2.

### Step 4: Match the formula with the options
Now, we need to check which of the provided options matches the formula for chloropicrin:
- COCl2: Not a match
- CH3Cl: Not a match
- CH3COCl: Not a match
- CCl3NO2: This matches the formula for chloropicrin.

### Step 5: Conclusion
Since CCl3NO2 is the only option that corresponds to the known tear gas chloropicrin, we can conclude that the correct answer is:

**The substance employed as a tear gas is CCl3NO2.**

### Final Answer
**Option D: CCl3NO2 (Chloropicrin)**

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