Qualitative Inorganic Salt Analysis Procedures
Preliminary Tests
| Experiment | Observation | Inference |
| Color of the salt | Colourless | Absence of Cu2+, Fe2+, etc. |
| Odour of the salt | Ammoniacal smell Vinegar smell | NH4+ Acetate ion |
| Solubility | In water with no precipitate with Na2CO3 In dilute HCl, soluble | NH4+ No Group 1 cations |
| Salt is heated in a dry test tube | Colorless gas turns lime water milky Reddish brown fumes Smell of ammonia Pleasant fruity smell | Carbonate Nitrate ion NH4+ Acetate ion |
| Flame test | Pale green Brick red | Ba2+ Ca2+ |
| Ash test | Blue ash | Al3+ |
Systematic Analysis for Anions
| Experiment | Observation | Inference |
| Dilute HCl is added to a little of the salt | Brisk effervescence of a colorless gas | CO32- |
| Salt is rubbed with dilute H2SO4 in a watch glass | Vinegar smell | Acetate |
| Salt is heated with concentrated H2SO4 | Colorless pungent smelling gas is evolved and dense white fumes are produced when a glass rod dipped in NH4OH is held near the mouth of the test tube | Chloride |
| Salt is heated with concentrated H2SO4 | Reddish brown vapors | Nitrate |
| Salt is acidified with dilute HCl and BaCl2 | White precipitate | Sulphate |
Systematic Analysis for Cations
| Experiment | Observation | Inference |
| To aqueous salt solution, sodium carbonate solution is added | No precipitate | Ammonium |
| Dilute HCl is added to a little of the salt solution | White precipitate | Lead |
| Solid NH4Cl added to salt solution of NH4OH | White gelatinous precipitate | Al3+ |
| Solid NH4Cl is added to salt, then NH4OH and (NH4)2CO3 added | White precipitate | Ba2+ or Ca2+ |
Confirmatory Tests for Anions
Carbonate
| The above gas is passed through lime water | Lime water turns milky |
| A few drops of BaCl2 solution are added | White precipitate |
Chloride
| Acidified with dilute HNO3 and drops of silver nitrate added | White precipitate soluble in NH4OH |
| Salt is heated with manganese dioxide and concentrated sulphuric acid | Greenish yellow gas |
Acetate
| Salt is warmed with concentrated H2SO4 and ethyl alcohol, then poured into excess water in a beaker | Fruity smell |
| To salt solution, neutral ferric chloride solution is added | Red color formed |
Nitrate
| Freshly prepared ferrous sulphate solution is added to a little of the salt solution and then concentrated H2SO4 is added along the sides of the test tube | Brown ring is formed at the junction of the solution |
| Salt solution, acetic acid, and lead acetate are added | Blue coloration |
Sulphate
| To salt solution, acetic acid and lead acetate solution are added | White precipitate |
| Excess ammonium acetate solution is added to the above precipitate | Precipitate is dissolved |
Confirmatory Tests for Cations
Ammonium Ion
| To salt solution, NaOH solution is added and then Nessler’s reagent | Reddish brown precipitate |
| Salt solution is heated with NaOH solution | Smell of ammonia and dense white fumes are produced when a glass rod is brought near the mouth of the test tube |
Aluminum
| Group III precipitate is dissolved in dilute HCl and 2 drops of litmus solution are added; then NH4OH is added dropwise | Blue precipitate floating in the colorless solution |
| Salt is dissolved in 2 drops of concentrated HNO3 and boiled with a few drops of cobalt nitrate solution. A filter paper soaked in this solution is burnt to ashes | Blue ash |
Barium
| A little acetic acid and potassium chromate solution are added to a little of the salt solution | Yellow precipitate |
| Flame test | Pale green color is imparted to the flame |
Calcium
| To salt solution, ammonium chloride, NH4OH, and ammonium oxalate solutions are added | White crystalline precipitate |
| Flame test | Brick red color is imparted to the flame |