Question

How will you prepare following from ethene.
(i) Ethanol
(ii) Formaldehyde

Answer 1

Hint: Carbon, hydrogen and oxygen atoms are present in ethanol molecules. They are used as fuel and solvents, and alcoholic beverages also contain ethanol. Formaldehyde is a naturally occurring organic compound. The pure compound is a colourless gas with a pungent scent. Hydrolysis of ethane can form ethanol and oxidation of ethane can form formaldehyde.

Complete step by step answer:
With the hydration of ethene, ethanol can be made. In this reaction, in the presence of a phosphoric acid catalyst (to speed up the reaction), ethene (which comes from cracking crude oil fractions) is heated with steam:
 $ {\text{ethene}} + {\text{steam}}\xrightarrow[{{\text{high pressure}}}]{{{\text{high temperature}}}}{\text{ethanol}} $

 $ {C_2}{H_4} + {H_2}O\xrightarrow[{{\text{high pressure}}}]{{{\text{high temperature}}}}{C_2}{H_5}OH $
Usually, this reaction uses a temperature of about $ 300{\text{ }}^\circ {\text{ }}C $ and an ambient pressure of around 60-70.
Note that the sole product is ethanol. The process is continuous, and ethanol will be generated as long as ethene and steam are fed into one end of the reaction vessel. Those characteristics make it an effective operation. Ethene, however, is derived from crude oil, which is a resource that is not renewable.
Ethene can be converted by ethene ozonolysis into formaldehyde followed by hydration in the presence of $ Zn $ and $ H_20 $ .By ozonolysis, oxidative cleavage. If this is ethene, this actually contributes to formaldehyde. In this case, the formation of formaldehyde can be seen.
 $ {H_2}C = C{H_2}\xrightarrow[{(ii)Zn/H20}]{{(i)O3,CH2Cl2}}2HCHO $ .

Note:
Formaldehyde is a strong-smelling, colourless gas used in the manufacture of construction materials and many household items. It is used in items made of pressed wood, such as particleboard, plywood, and fibreboard; glues and adhesives; fabrics made of permanent press; coatings of paper products; and some insulation materials.
In the manufacturing of varnishes and perfumes, ethanol is commonly used as a solvent; as a preservative for biological specimens; in the preparation of essences and flavourings; in many medications and medicines; as a disinfectant and in tinctures (e.g., iodine tincture); and as a fuel and gasoline additive.