1. An organic compound Ⓐ of molecular formula C2H6O is Ethanol CH3 -CH2OH.
2. Ethanol reacts with thionyl chloride in the presence of pyridine to give CH3 -CH2Cl Ⓑ as product.
3. Ethyl chloride on treatment with alcoholic KOH, undergoes dehydrohalogenation to give C2H4 , ethylene Ⓒ as the product.
4. Ethylene on reaction with Cl2 yield ethylene dichioride as Ⓓ as the product.