ISSR CLASSES
Checkpoint Science
iGCSE Chemistry
iGCSE Physics
iGCSE Coordinated Science
A-Level Chemistry
PRACTICALS
Practicals Home
Practicals A-Z
Study Plan for Practical Work
Hydrogen chloride, hydrogen bromide and hydrogen iodide are all colourless gases.
1 Reaction with ammonia gas
These colourless acidic gases are all very soluble in water and fume in moist air. They turn damp, blue litmus paper red. In the presence of ammonia gas a dense white smoke of solid ammonium halide forms:
|
NH3(g) + HCl(g) ⇒ NH4Cl(s) |
Video - testing for a hydrogen halide with ammonia
2 Solubility in water
|
The hydrogen halides are all highly soluble in water forming strongly acidic solutions. Hydrogen chloride gives hydrochloric acid, hydrogen bromide gives hydrobromic acid and hydrogen iodide forms hydroiodic acid. The high solubility in water is seen if a test tube of the gas is inverted into a beaker of water. The gas dissolves forcing the water to rise up the test tube. A more impressive demonstration is the fountain experiment. |
|
Video - hydrogen chloride gas dissolves in water
Video - the fountain experiment
