Answer:

Reaction of ethene with HCl

The reaction of ethene (C2H4) with hydrogen chloride (HCl) is an example of an addition reaction. In this reaction, the double bond in ethene is broken, and the hydrogen atom from HCl and the chlorine atom from HCl are added to the carbon atoms of ethene.

Explanation

When ethene is reacted with hydrogen chloride, the double bond between the carbon atoms is broken, resulting in a rearrangement of electrons. The hydrogen atom from HCl adds to one carbon atom of ethene, while the chlorine atom adds to the other carbon atom.

The reaction can be represented as follows:

C2H4 + HCl → CH3CH2Cl

The product formed is chloroethane (CH3CH2Cl). Chloroethane is an alkyl halide with one chlorine atom attached to one of the carbon atoms of ethane.

Reasoning

The reaction of ethene with HCl results in the formation of chloroethane. This is because the double bond in ethene allows for the addition of atoms or groups to the carbon atoms. In this case, the hydrogen atom from HCl adds to one carbon atom, and the chlorine atom adds to the other carbon atom.

The addition of the hydrogen and chlorine atoms to the carbon atoms of ethene forms a new carbon-carbon single bond and a new carbon-hydrogen bond. This results in the formation of chloroethane.

Conclusion

Therefore, the correct answer is option 'A' - chloroethane. When ethene is reacted with HCl, chloroethane is formed as the product.