MCQ Detailed View

Ozonolysis is a reaction in which ozone (O₃) reacts with alkenes to break the carbon-carbon double bond and form ozonides. When ethene (CH₂=CH₂) undergoes ozonolysis, it first reacts with ozone to form an unstable molozonide intermediate. This rearranges to form a more stable ozonide. On hydrolysis using water or a reducing agent like zinc and water, the ozonide breaks down to give carbonyl compounds.

In the case of ethene, both carbon atoms are bonded to hydrogen. Upon ozonolysis and hydrolysis, each carbon of the double bond is converted into a molecule of formaldehyde (HCHO). The reaction is as follows:

CH₂=CH₂ + O₃ → [ozonide intermediate] → hydrolysis → 2HCHO

This reaction is a key method used in organic chemistry to determine the position of double bonds in alkenes by identifying the carbonyl products. Ozonolysis of symmetric alkenes like ethene yields only one type of product.

Ethylene oxide is an epoxide and is not formed in ozonolysis. Ethylene glycol (HO–CH₂–CH₂–OH) is a diol formed by hydroxylation, not ozonolysis. Ethyl alcohol (CH₃CH₂OH) is an alcohol and not a product of this reaction.

Formaldehyde is the simplest aldehyde and is the correct product of ozonolysis of ethene. This knowledge is important in the study of reaction mechanisms in organic chemistry, especially for identifying structural features in alkenes.