Qualitative analysis
How to do salt analysis · Viva · Quiz
To analyse the given inorganic salt for one acidic and one basic radical.
| Experiment | Observation | Inference |
|---|---|---|
| Warm the solid salt with dilute H₂SO₄ | Brown fumes of NO₂ are evolved | NO₂⁻ may be present |
| Confirmatory Tests | ||
| Potassium Iodide Starch Test Take evolved gas and add KI + starch solution acidified with acetic acid | Blue colour appears | NO₂⁻ is confirmed |
| Sulphanilic Acid / 1-Naphthylamine Test Acidify 1 mL of water extract with acetic acid and add sulphanilic acid solution followed by 1-naphthylamine reagent | Red colour is formed | NO₂⁻ is confirmed |
| Experiment | Observation | Inference |
|---|---|---|
| Flame test in a clean non-luminous flame | Intense yellow flame | Na⁺ may be present |
| Confirmatory Test | ||
| Zinc Uranyl Acetate Test Take a filtrate and add zinc uranyl acetate solution | Yellow crystalline precipitate | Na⁺ is confirmed |
The given salt contains Na⁺ as the cation (basic radical) and NO₂⁻ as the anion (acidic radical). The salt is Sodium Nitrite (NaNO₂).