Lassaigne's test (detection of N, S, halogens) (Sodium fusion converts organic N→NaCN, S→Na₂S, X→NaX; detected by specific color tests)

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Sodium fusion converts organic N→NaCN, S→Na₂S, X→NaX; detected by specific color tests

What each symbol means

SymbolWhat it stands for
NaSodium metal (fusion agent)
NaXSodium halide (X = Cl, Br, I)
NaCNSodium cyanide (indicates nitrogen)
Na₂SSodium sulfide (indicates sulfur)

When to use this

Organic compound heated with excess Na in ignition tube to red heat → plunged into distilled water → filtered = Lassaigne's extract. All elements converted to ionic form for wet testing.