Select the alkyne listed below that, upon treatment with ozone followed by water, would not produce carbon dioxide and a carboxylic acid as the final products?
o 1-pentyne
o propyne
o 1-butyne
o 1-hexyne
o ethyne

The only exception is Ethyne

Explanation:

Homologous members of alkynes formed ozonide and when treated with ozone and water, then decomposed to form ketones which are then oxidized to carbon dioxide and carboxylic acids.

Ethyne( Acetylene) is an exception as it gives glyoxal as well as formic acid on reacting with ozone.

C2H2 + O3 ==> OCHCHO + HCO2H

Therefore, Ethyne is the only exception.

the answer is barium and copper bromide