Which of the following compounds is formed by ozonolysis of $2-\mathrm{butyne}$?

• A. $2$ molecules of $\mathrm{acetic}\mathrm{acid}$
• B. $\mathrm{ethanol}$ and $\mathrm{carbon}\mathrm{monoxide}$
• C. $\mathrm{acetone}$ and $\mathrm{carbon}\mathrm{dioxide}$
• D. $2$ molecules of $\mathrm{formic}\mathrm{acid}$

Answer: (A)

Verified step by step guidance

1. Identify the structure of 2-butyne. It is an alkyne with the triple bond between the second and third carbon atoms in a four-carbon chain: CH3-C\equiv C-CH3.
2. Recall that ozonolysis of alkynes cleaves the triple bond and typically forms carboxylic acids or other oxidized products depending on the substituents attached to the alkyne carbons.
3. Write the general ozonolysis reaction for an internal alkyne: R-C\equiv C-R' + O3 + H2O \rightarrow 2 RCOOH (carboxylic acids).
4. Apply this to 2-butyne, where both sides of the triple bond are methyl groups (CH3). Each side will be converted into acetic acid (CH3COOH) upon ozonolysis.
5. Conclude that ozonolysis of 2-butyne produces 2 molecules of acetic acid.