How will you prove:
presence of acetylenic hydrogen in 1-butyne.

Explanation

When 1-butyne is treated with ammoniacal cuprous chlotide a red precipitate of cuprous 1-butynide is obtained. Again , when an aqueous solution of silver nitrate is added to the alcoholic solution of 1-butyne, a white precipitate of silver 1-butynide is obtained.
`underset("1-butyne")(CH_3CH_2C-=CH)overset(Cu_2Cl_2)underset(NH_4OH)tounderset("Cuprous 1-butynide")(CH_3CH_2C-=C""Cudarr(red))`
`underset(1-"butyne")(CH_3CH_2C-=CH)overset(AgNO_3)underset("Alcohol")tounderset("Silver 1-butynide")(CH_3CH_2C-=CAgdarr(white))`