• 2 Butyne is not terminal alkyne but 1 butyne is a a terminal alkyne. when1 butyne reacts with ammoniacal AgNO3 and it gives a white precipitate of silver butynide . But 2 butyne does not give a white precipitate and hence Ammoniacal silver nitrate can be used to distinguish 1 butyne from 2 butyne.

2CH3CH2CCH + 2AgNO3 + 2NH4OH——› 2CH3CH2CCAg + 2NH4NO3 + 2H2O

2CH3CCCH3 + 2AgNO3 + 2NH4OH ——›

Distinguishing between 1-hexyne and 2-hexyne can be done using ammoniacal AgNO3 solution and ammoniacal solution of Cu(II) tartarate. Let's understand why these reagents are suitable for this purpose.

1. Ammoniacal AgNO3 solution:
- When 1-hexyne is treated with ammoniacal AgNO3 solution, a yellow precipitate of silver acetylide (AgC2H) is formed. This reaction occurs due to the terminal alkyne nature of 1-hexyne, which allows it to form a complex with silver ions.
- On the other hand, 2-hexyne does not react with ammoniacal AgNO3 solution because it is an internal alkyne, meaning it does not have a terminal alkyne group.
- Therefore, the formation of a yellow precipitate with ammoniacal AgNO3 solution indicates the presence of 1-hexyne.

2. Ammoniacal solution of Cu(II) tartarate:
- When 2-hexyne is treated with ammoniacal solution of Cu(II) tartarate, a deep blue color is observed due to the formation of a complex between the copper ion and the alkyne group.
- On the other hand, 1-hexyne does not react with the ammoniacal solution of Cu(II) tartarate, and hence, no color change is observed.
- Therefore, the presence of a deep blue color with ammoniacal solution of Cu(II) tartarate indicates the presence of 2-hexyne.

3. Cold, dilute and alkaline KMnO4:
- Cold, dilute and alkaline KMnO4 can be used to oxidize alkynes. However, it does not specifically distinguish between 1-hexyne and 2-hexyne. Both isomers will react in a similar way to form carboxylic acids.
- Therefore, this reagent is not suitable for distinguishing between 1-hexyne and 2-hexyne.

4. H2SO4/HgSO4:
- H2SO4/HgSO4 is commonly used to convert alkynes into aldehydes or ketones through tautomerization. However, it does not provide a specific test to differentiate between 1-hexyne and 2-hexyne.
- Therefore, this reagent is not suitable for distinguishing between 1-hexyne and 2-hexyne.

In summary, the ammoniacal AgNO3 solution and ammoniacal solution of Cu(II) tartarate are the suitable reagents for distinguishing between 1-hexyne and 2-hexyne. The formation of a yellow precipitate with ammoniacal AgNO3 solution indicates the presence of 1-hexyne, while the deep blue color with ammoniacal solution of Cu(II) tartarate indicates the presence of 2-hexyne.