Chemistry · Alkynes: Acidic character, addition of hydrogen, halogens, water and hydrogen halides, polymerization
Acetylene gives precipitate with ammonical silver nitrate is due to:
Acetylene gives precipitate with ammonical silver nitrate is due to:
- A. Acetylene possess \( s p^{2} \) carbon
- B. Acetylene posses acidic hydrogen
- C. Acetylene possess low electronegative carbon
- D. Acetylene posess - \( C \equiv C \) -triple bond
Step-by-step solution
Acetylene (C2H2) has terminal hydrogens attached to sp-hybridized carbons, which are relatively acidic (pKa ≈ 25). In the presence of ammonical silver nitrate (Tollens' reagent), these acidic hydrogens are replaced by silver ions, forming a white precipitate of silver acetylide (Ag2C2). Option B correctly identifies this property. Option A is incorrect because acetylene has sp-hybridized carbon, not sp2. Option C is misleading; low electronegativity is not the direct cause. Option D is true but insufficient since internal alkynes lacking terminal hydrogen do not give this precipitate.