17. Lead

1. $H_2S$

$Pb^{2+}$ $+$ $S^{2-}$ $\longrightarrow$ $PbS$ - Black precipitate - Soluble in $HNO_3$

2. $Cl^-$

$Pb^{2+}$ $+$ $2Cl^-$ $\longrightarrow$ $PbCl_2$ - White crystalline precipitate - Soluble in hot water - Complexed with fuming $HCl$ $PbCl_2$ $+$ $2Cl^-$ $\longrightarrow$ $PbCl_4^{2-}$ - Tetrachloroplombate(II) - Soluble, colorless

3. $I^-$

$Pb^{2+}$ $+$ $2I^-$ $\longrightarrow$ $PbI_2$ - yellow precipitate - Soluble in $KOH$

4. $KOH$

$Pb^{2+}+2OH^- \longrightarrow Pb(OH)_2$ - White gelatinous precipitate - Soluble in $HNO_3$ - Soluble in a large excess of reagent: $Pb(OH)_2$ $+$ $OH^-$ $\longrightarrow$ $Pb(OH)_3^-$ - Trihydroxoplombate(II) - Soluble, colorless

5. $NH_3$

$Pb^{2+}$ $+$ $2OH^-$ $\longrightarrow$ $Pb(OH)_2$ - White gelatinous precipitate - Insoluble in excess reagent

6. $SO_4^{2-}$

(partir de très peu de sulfate) $Pb^{2+}$ $+$ $2SO_4^{2-}$ $\longrightarrow$ $PbSO_4$ - White precipitate - Soluble in $NH_3$/acetic acid. - Soluble in $NH_3$/tartaric acid . - Soluble in hot $HNO_3$ .

7. $CrO_4^{2-}$

$Pb^{2+}$ $+$ $CrO_4^{2-}$ $\longrightarrow$ $PbCrO_4$ - Yellow precipitate - Soluble in cold $KOH $ - Soluble in cold $HNO_3$.