Qualitative Inorganic Analysis - Chemical & Empirical Formulas

Vocabulary practice flashcards for Qualitative Inorganic Analysis covering Experiments 6 through 9, including chemical and empirical formulas, confirmatory reagents, products, flame tests, and visual observations.

Chemical (Molecular) Formula

Reflects the exact number of atoms of each element in a formula unit or molecule.

Empirical Formula

Represents the simplest whole-number ratio of atoms present in a compound.

Ammonium Sulfide Group

Group cations precipitated as sulfides or hydroxides using ammonium sulfide $(NH_4)_2S$ ($[N_2H_8S]$) or hydrogen sulfide $H_2S$ in ammoniacal buffer.

Alkaline Earth Group

Ammonium Carbonate Group $(NH_4)_2CO_3$ ($[N_2H_8CO_3]$) cations identified via precipitation and flame tests.

Soluble Cation Group (Alkali Metals)

Group V cations that do not form insoluble precipitates with earlier group reagents.

Aluminon

Reagent with chemical and empirical formula $C_{22}H_{23}N_3O_9$ used to identify Aluminum ($Al^{3+}$).

Aluminum ($Al^{3+}$) Confirmatory Test

Reaction with Aluminon ($C_{22}H_{23}N_3O_9$) yielding an Aluminum-Aluminon Complex observed as a red lake precipitate.

Chromium(III) ($Cr^{3+}$) Confirmatory Test

Reaction with Lead Acetate ($Pb(CH_3COO)_2$) yielding Lead Chromate ($PbCrO_4$) as a yellow ppt.

Zinc ($Zn^{2+}$) Confirmatory Test

Reaction with Hydrogen Sulfide ($H_2S$) yielding Zinc Sulfide ($ZnS$) as a white ppt.

Manganese(II) ($Mn^{2+}$) Confirmatory Test

Reaction with Sodium Bismuthate ($NaBiO_3$) + $HNO_3$ yielding Permanganic Acid ($HMnO_4$) as a purple solution.

Iron(III) ($Fe^{3+}$) Confirmatory Test

Reaction with Ammonium Thiocyanate ($NH_4SCN$) yielding an Iron Thiocyanate Complex ($[Fe(SCN)]^{2+}$) as a blood-red solution.

Cobalt(II) ($Co^{2+}$) Confirmatory Test

Reaction with Ammonium Thiocyanate + Acetone ($C_3H_6O$) yielding Tetrathiocyanatocobaltate ($[Co(SCN)_4]^{2-}$) as a blue organic layer.

Nickel(II) ($Ni^{2+}$) Confirmatory Test

Reaction with Dimethylglyoxime / DMG ($C_4H_8N_2O_2$) yielding Nickel DMG ($Ni(C_4H_7N_2O_2)_2$) as a cherry-red ppt.

Barium ($Ba^{2+}$) Confirmatory Test

Reaction with Potassium Chromate ($K_2CrO_4$) yielding Barium Chromate ($BaCrO_4$) as a yellow ppt and a yellow-green flame test.

Strontium ($Sr^{2+}$) Confirmatory Test

Reaction with $K_2CrO_4$ + Ethanol ($C_2H_5OH$) yielding Strontium Chromate ($SrCrO_4$) as a yellow ppt and a carmine-red flame test.

Calcium ($Ca^{2+}$) Confirmatory Test

Reaction with Potassium Oxalate ($K_2C_2O_4$) yielding Calcium Oxalate ($CaC_2O_4$) as a white ppt and a brick-red flame test.

Magnesium ($Mg^{2+}$) Confirmatory Test

Reaction with Titan Yellow ($C_{28}H_{19}N_5Na_2O_6S_4$) yielding Magnesium Hydroxide Lake ($Mg(OH)_2$) as a red gelatinous ppt.

Potassium ($K^+$) Confirmatory Test

Reaction with Sodium Cobaltinitrite ($Na_3Co(NO_2)_6$) yielding Potassium Cobaltinitrite ($K_3Co(NO_2)_6$) as a yellow ppt and a violet flame test through cobalt glass.

Sodium ($Na^+$) Confirmatory Test

Reaction with Zinc Uranyl Acetate ($ZnUO_2(CH_3COO)_4$) yielding Sodium Zinc Uranyl Acetate ($NaZn(UO_2)_3(CH_3COO)_9$) as a yellow ppt and a persistent yellow flame test.

Lithium ($Li^+$) Confirmatory Test

Reaction with Disodium Phosphate ($Na_2HPO_4$) yielding Lithium Phosphate ($Li_3PO_4$) as a white ppt and a carmine-red flame test.

Ammonium ($NH_4^+$) Confirmatory Test

Reaction with Nessler's Reagent ($K_2[HgI_4]$) yielding Iodide of Millon's Base ($HgO \cdot HgNH_2I$) as an orange-red ppt with no flame test.

Sulfide ($S^{2-}$) Analysis

Reaction with Lead Acetate ($Pb(CH_3COO)_2$) producing Lead Sulfide ($PbS$) as a black ppt.

Carbonate ($CO_3^{2-}$) Analysis

Reaction with Hydrochloric Acid ($HCl$) producing Carbon Dioxide ($CO_2$) observed as effervescence.

Sulfite ($SO_3^{2-}$) Analysis

Reaction with Barium Acetate ($Ba(CH_3COO)_2$) + $H_2O_2$ producing Barium Sulfate ($BaSO_4$) as a white ppt.

Sulfate ($SO_4^{2-}$) Analysis

Reaction with Barium Chloride ($BaCl_2$) producing Barium Sulfate ($BaSO_4$) as a white ppt.

Phosphate ($PO_4^{3-}$) Analysis

Reaction with Ammonium Molybdate ($(NH_4)_2MoO_4$) producing Ammonium Phosphomolybdate ($(NH_4)_3PMo_{12}O_{40}$) as a yellow ppt.

Borate ($BO_3^{3-}$) Analysis

Reaction with Methanol ($CH_3OH$) + $H_2SO_4$ producing Methyl Borate ($B(OCH_3)_3$) observed as a green flame.

Chloride ($Cl^-$) Analysis

Reaction with Silver Nitrate ($AgNO_3$) producing Silver Chloride ($AgCl$) as a white ppt.

Bromide ($Br^-$) Analysis

Reaction with Chlorine Water ($Cl_2$) + $CCl_4$ producing Free Bromine ($Br_2$) observed as orange/yellow in the $CCl_4$ layer.

Iodide ($I^-$) Analysis

Reaction with Sodium Nitrite ($NaNO_2$) + $CCl_4$ producing Free Iodine ($I_2$) observed as violet in the $CCl_4$ layer.

Thiocyanate ($SCN^-$) Analysis

Reaction with Iron(III) Chloride ($FeCl_3$) producing Iron Thiocyanate Complex ($[Fe(SCN)]^{2+}$) as a blood-red result.

Nitrite ($NO_2^-$) Analysis

Reaction with Urea ($(NH_2)_2CO$) + $HCl$ producing Nitrogen Gas ($N_2$) observed as vigorous gas evolution.

Nitrate ($NO_3^-$) Analysis

Reaction with Iron(II) Sulfate ($FeSO_4$) + $H_2SO_4$ producing Nitrosyliron Complex ($[Fe(H_2O)_5(NO)]^{2+}$) as a Brown Ring.

Chlorate ($ClO_3^-$) Analysis

Reaction with Sodium Nitrite ($NaNO_2$) + Silver Nitrate ($AgNO_3$) producing Silver Chloride ($AgCl$) as a white ppt.

Dimethylglyoxime (DMG)

Organic reagent with chemical formula $C_4H_8N_2O_2$ and empirical formula $C_2H_4NO$.

Lead Acetate

Reagent with chemical formula $Pb(CH_3COO)_2$ and empirical formula $PbC_4H_6O_4$.

Acetate Ion

Anion with chemical formula $CH_3COO^-$ and empirical formula $C_2H_3O_2$.

Oxalate Ion

Anion with chemical formula $C_2O_4^{2-}$ and empirical formula $CO_2$.

Ammonium Thiocyanate

Reagent with chemical formula $NH_4SCN$ and empirical formula $CH_4N_2S$.

Potassium Oxalate

Reagent with chemical formula $K_2C_2O_4$ and empirical formula $KCO_2$.

Calcium Oxalate

Product compound with chemical formula $CaC_2O_4$ and empirical formula $CaCO_2$.

Ethanol

Reagent with chemical formula $C_2H_5OH$ and empirical formula $C_2H_6O$.