Write IUPAC name of the given compound: CH₂=CHCl

To determine the IUPAC name for the compound with the formula \(\text{CH}_2\text{=CHCl}\), follow these steps:

1. **Identify the longest carbon chain containing the double bond:** The given compound has two carbon atoms connected by a double bond. Therefore, the base name for this compound is "ethene" (since "ethene" is the name for a two-carbon chain with a double bond).

2. **Identify and name the substituents:** There is a chlorine atom attached to the second carbon of the double-bonded chain. In the IUPAC naming system, substituents are named and numbered according to their position on the main carbon chain.

3. **Number the carbon chain:** The double bond starts from carbon 1, so the chlorine substituent is on carbon 2.

4. **Combine the substituent and base name:** The substituent (chlorine) is named as "chloro," and since it is on the second carbon, it is positioned at carbon 2.

Putting it all together:

- The base name is "ethene."
- The substituent is "chloro," and it is on the second carbon.

Therefore, the IUPAC name of \(\text{CH}_2\text{=CHCl}\) is **2-chloroethene**.