These are important qualitative tests in organic chemistry:

Test	Reagent	Detects	Positive observation
Baeyer’s test	Cold, dilute alkaline KMnO₄	C=C / C≡C unsaturation	Purple KMnO₄ decolourises; brown MnO₂ may form
Ammoniacal AgNO₃ test	AgNO₃ + NH₃ (ammoniacal AgNO₃)	Terminal alkynes	White/grey silver acetylide precipitate
Br₂/CCl₄ test	Bromine in CCl₄	C=C / C≡C unsaturation	Reddish-brown bromine colour disappears

JEE/NEET shortcut

• Baeyer test → Unsaturation
• Br₂/CCl₄ → Unsaturation
• Ammoniacal AgNO₃ → Terminal alkyne specifically

Important: Internal alkynes do not give the ammoniacal AgNO₃ test because they don’t have the acidic terminal ≡C–H hydrogen.

Sure. Here are the reactions of each test:

1. Baeyer’s Test — KMnO₄

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2. Ammoniacal AgNO₃ — Terminal Alkyne

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3. Br₂/CCl₄ Test