Distinction between pairs of compounds
But-1-yne and But-2-yne

Explanation

But-1-yne and but-2-yne are terminal and non-terminal alkynes respectively. Following tests help to distinguish these.
(a)With ammoniacal Cuprous Chloride Solution . but-1-yne gives red ppt. while but-2-yne does not.
`CH_(3)underset("But-1-yne")(CH_(2)C)-=CH+[Cu(NH_(3))_(2)]^(+)OH^(-)rarrundersetunderset(("Red ppt."))("Copper-1-butynide")(CH_(3)CH_(2)C-=C Cu)+2NH_(3)+H_(2)O`
(b) With Tollen.s reagent,1-butyne gives white ppt. of silver acetylide while 2-butyne does not.
`underset("1-Butyne")(CH_(3)CH_(2)C)-=CH+[Ag(NH_(3))_(2)]^(+)OH^(-)rarrundersetunderset(("White ppt."))("Silver 1-butynide")(CH_(3)CH_(2)C-=CAg)darr+2NH_(3)+H_(2)O`