List of reactions

Topics:

Identification of unknown compounds

Detection of C and H

C + 2 CuO \to_{}^{Δ} 2 Cu + C_{O 2}

H + CuO \to_{}^{Δ} Cu + H_{2} O

{CO}_{2} + {Ca (OH)}_{2} \to_{}^{} {CaCO}_{3} ↓ + H_{2} O

\underset{White}{{CuSO}_{4}} + 5 H_{2} O \to_{}^{} \underset{Blue}{{CuSO}_{4} {.5H}_{2} O}

Lassaigne extracts

Na + C + N \to_{}^{Δ} NaCN

2 Na + S \to_{}^{Δ} {Na}_{2} S

Na + X \to_{}^{Δ} NaX

Na + S + C + N \to_{}^{Δ} NaCNS

Detection of nitrogen

{Fe}^{+ 2} + 6 {CN}^{-} \to_{}^{} {[{Fe}^{(+ 2)} {(CN)}_{6}^{(- 6)}]}^{- 4}

{Fe}^{+ 2} \to_{}^{Conc H_{2} {SO}_{4}} {Fe}^{+ 3} + e^{-}

3 {[{Fe}^{(+ 2)} {(CN)}_{6}^{(- 6)}]}^{- 4} + 4 {Fe}^{+ 3} \to_{}^{} \underset{Prussian blue}{{Fe}_{4}^{(+ 3)} {[{Fe}^{(+ 2)} {(CN)}_{6}^{(- 6)}]}_{3}^{(- 4)}}

When sulphur is present and less Na was used in LE:

3 {CNS}^{-} + {Fe}^{+ 3} \to_{}^{} \underset{Blood red color}{{Fe (CNS)}_{3}}

Detection of sulphur

S^{- 2} + {[{Fe}^{(+ 2)} {(CN)}_{5}^{(- 5)} {NO}^{(+ 1)}]}^{- 2} \to_{}^{} \underset{Violet color}{{[{Fe}^{(+ 2)} {(CN)}_{5}^{(- 5)} {NOS}^{(- 1)}]}^{- 4}}

{Pb}^{+ 2} + S^{- 2} \to_{}^{} \underset{Black precipitate}{PbS}

Detection of halogens

AgN O_{3} + \underset{(X = Cl,Br,I)}{NaX} \to_{}^{} NaN O_{3} + AgX

AgCl is a white precipitate that is soluble in NH₄OH
AgBr is a pale yellow precipitate that is partly soluble in NH₄OH
AgI is a dark yellow precipitate that is insoluble in NH₄OH

Organic layer test:

2 {Br}^{-} + 2 {Cl}_{2} \to_{}^{} \underset{Orange color}{{Br}_{2} + 2 {Cl}^{-}}

2 I^{-} + 2 {Cl}_{2} \to_{}^{} \underset{Violet color}{I_{2} + 2 {Cl}^{-}}

16 H^{+ 1} + 2 {MnO}_{4}^{-} + 10 {Br}^{-} \to_{}^{} \underset{Orange color}{5 {Br}_{2}} + 2 {Mn}^{+ 2} + 8 H_{2} O

16 H^{+ 1} + 2 {MnO}_{4}^{-} + 10 I^{-} \to_{}^{} \underset{Violet color}{5 I_{2}} + 2 {Mn}^{+ 2} + 8 H_{2} O