Salt Analysis (Qualitative Analysis) Flashcards

Vocabulary flashcards covering Qualitative Salt Analysis definitions, cation colors, named colored compounds, deliquescent salts, and Bunsen flame characteristics.

Basic Radical

The positively charged cation in a salt, such as $Na^+$ in $NaCl$, derived from a base during neutralization.

Acidic Radical

The negatively charged anion in a salt, such as $Cl^-$ in $NaCl$, derived from an acid during neutralization.

Heavy Salts

Salts containing heavy metal cations, specifically $Ba$, $Pb$, and $Hg$.

Light Salts

Salts containing light metal cations, specifically $Mg$, $Al$, $Ca$, and $Zn$.

Deliquescent Salts

Salts formed by cations like $Mg$, $Al$, $Ca$, $Zn$, $Ba$, $Pb$, or $Hg$ with anions like $NO_3^-$ or $Cl^-$ that absorb atmospheric moisture.

Qualitative Salt Analysis Overview

The systematic process of analyzing basic and acidic radicals using physical/dry tests (density, colour, solubility in water, action of heat, flame test, borax bead test) and wet/confirmatory tests.

Cation Colors in Aqueous Solution

In hydrated or aqueous solutions, $Mn^{2+}$ and $Co^{2+}$ are pink; $Cr^{3+}$, $Fe^{2+}$, and $Ni^{2+}$ are green; $Cr^{6+}$ and $Fe^{3+}$ are yellow; and $Cu^{2+}$ is blue.

Green Vitriol

Hydrated ferrous sulfate represented by the chemical formula $FeSO_4 \cdot 7H_2O$ or $[Fe(H_2O)_6]SO_4 \cdot H_2O$.

Mohr Salt

Ferrous ammonium sulfate hexahydrate with the formula $FeSO_4 \cdot (NH_4)_2SO_4 \cdot 6H_2O$, which exhibits a pale green color.

Rinmann's Green

A green compound formed by cobalt oxide and zinc oxide with the formula $CoO \cdot ZnO$.

Peligot Salt

Potassium chlorochromate with the chemical formula $KCrO_3Cl$.

Thenard's Blue

A blue compound composed of cobalt oxide and aluminum oxide with the formula $CoO \cdot Al_2O_3$.

Perchromate ($CrO_5$)

A blue chromium peroxide compound characterized by a butterfly structure.

Turnbull's Blue

A blue coordination complex with the chemical formula $Fe_3[Fe(CN)_6]_2$.

Prussian Blue

A deep blue coordination complex with the chemical formula $Fe_4[Fe(CN)_6]_3$.

Schwitzer's Reagent

A deep blue complex solution containing tetraamminecopper(II) sulfate, $[Cu(NH_3)_4]SO_4$.

Red Lead (Minium / Sindur)

A red mixed lead oxide compound with the formula $Pb_3O_4$.

Chromyl Chloride

A red liquid compound with the chemical formula $CrO_2Cl_2$.

Scarlet Red Compound

Mercuric iodide with the formula $HgI_2$.

Chocolate Brown Compound

Copper ferrocyanide with the chemical formula $Cu_2[Fe(CN)_6]$.

Brown Ring Complex

The brown complex formed during the nitrate test with the chemical formula $[Fe(H_2O)_5(NO)]SO_4$.

Copper(II) Chloride Solution Colors

Dilute $CuCl_2$ solution is blue due to $[Cu(H_2O)_4]^{2+}$; adding $HCl$ turns it yellow due to $[CuCl_4]^{2-}$; concentrated $CuCl_2$ is green due to the presence of both $[Cu(H_2O)_4]^{2+}$ and $[CuCl_4]^{2-}$.

Non-Luminous Flame

The oxidising flame in a Bunsen burner, representing the hottest zone located above the reducing zone.

Luminous Flame

The reducing flame in a Bunsen burner containing unburnt carbon particles.

Black Compounds Examples

Specific black compounds include $Cu_2CrO_4$, $BiI_3$, and mercurous ammonium precipitates $Hg(NH_2)Cl \downarrow + Hg \downarrow$ and $Hg(NH_2)NO_3 \downarrow + Hg \downarrow$.

Colored Compounds Summary

An overview of characteristic compound colors including red ($Pb_3O_4$, $CrO_2Cl_2$, $HgI_2$), blue ($[Cu(NH_3)_4]SO_4$, $CrO_5$), green ($FeSO_4 \cdot 7H_2O$), and black ($Cu_2CrO_4$, $BiI_3$).