a) lithium
Execution:
First, a magnesia stick is dipped in hydrochloric acid and then in lithium chloride. The stick is then held in the burner flame.
Observation:
The flame turns carmine.
b) ammonium ion
Execution:
Some ammonium sulfate is placed in a small vessel. A strip of indicator paper is moistened and stuck to the inside of a watch glass case. Then a few drops of hydrochloric acid are added to the ammonium sulfate and the watch glass bowl is held over the vapors that develop.
Observation:
The indicator paper turns blue because gaseous ammonia is produced, which reacts with the water in the indicator paper to form a base.
c) sulfate ions
Execution:
The ammonium sulfate is dissolved in water and treated with barium chloride solution.
Observation:
A white, poorly soluble precipitate of barium sulfate is formed.
d) presence of water
Execution:
Anhydrous copper sulfate, which is white, is added to the substance to be tested.
Observation:
In the presence of water, the salt turns light blue.
e) carbonate ions
Execution:
A few drops of hydrochloric acid are placed on the solid calcium carbonate.
Observation:
A gas evolution can be observed, during which carbon dioxide is produced.
f) iodide ions
Execution:
A potassium iodide solution is mixed with silver nitrate solution.
Observation:
A yellow precipitate of silver iodide is formed.
