Question

Write the names of product when ethene reacts with ${O_3}$
A.Acetaldehyde
B.Formaldehyde
C.Acetone
D.Formic acid

Answer 1

Hint: We can obtain products such as alcohols, carboxylic acids, aldehydes (or) ketones by the ozonolysis of alkenes.
Ozonolysis is an organic redox reaction that uses ozone to cleave the unsaturated bonds present in alkenes, azo compounds and alkynes.

Complete step by step answer:
We know that ozone is an active allotrope of oxygen. The oxidative cleavage of the alkyne (or) alkene takes place when alkenes and alkynes are reacted with ozone. The carbon-carbon double bond replaces the carbon-carbon triple bonds, and carbonyl products are formed. The carbon-carbon pi bond as well as the carbon-carbon sigma bond is broken by the ozone molecule. An intermediate known as ozonide is formed. We can eliminate the oxygen in the intermediate by the action of zinc dust. Based on the type of reactant and workup, the final product varies.
We can produce aldehydes or ketone when we use thiourea, dimethyl sulfide, zinc dust, triphenylphosphine during the ozonolysis of alkene. The product carboxylic acid is obtained when we use hydrogen peroxide during the ozonolysis of alkene.
Ozonolysis of ethene gives formaldehyde as the product. We can write the chemical reaction as,

Therefore, the option (B) is correct.

Note:
We must remember that the oleic acid ozonolysis is used to form azelaic acid and pelargonic acid on an industrial scale. Ozonolysis of alkynes gives the product as acid anhydride (or) diketone. Incomplete fragmentation takes place in ozonolysis of alkynes. No reducing agents are used. When the reaction takes place in presence of water, hydrolysis of acid anhydride takes place and two carboxylic acids are formed as products. We can determine the position of triple bonds in an unknown alkyne in ozonolysis of alkynes.