Identification of Gases
| Test | Observation | Inference |
|---|---|---|
| Using moist litmus paper and bromine solution | Greenish yellow gas with a pungent smell turns blue litmus paper red and bromine solution turns orange |
The gas is acidic
The gas is Cl2 gas |
| Using moist lead (II) ethanoate paper | Moist lead (II) paper turns black |
Product formed is lead (II) sulphide
The gas is H2S |
| Using litmus paper and FeSO4 solution | Reddish brown gas with a pungent smell turns blue litmus paper red and FeSO4 solution blue | The gas is NO2 gas |
| Using litmus paper and Concentrated hydrochloric acid | Colourless gas with a pungent smell turns red litmus paper blue and produces dense white fumes of reaction with HCl |
The white fumes produced is Ammonium chloride
The gas is alkaline The gas is NH3 |
| Using litmus paper and acidified solutions of K2Cr2O7 or KMnO4 | Colourless gas with a pungent smell turns blue litmus paper red, turns orange K2Cr2O7 solution green and purple KMnO4 colorless |
The gas is acidic The gas is a reducing agent The gas is likely SO2 |
Note: Hydrogen chloride gas turns blue paper red and reacts with Ammonia to form white dense fumes of ammonium chloride