The solubility in water of compounds formed between cations and anions:
2−
+
Li
2−
−
−
−
SO4
Cl
Br
I
OH
slightly
soluble
soluble
soluble
soluble
slightly
soluble
+
−
CO3
−
NO3
+
soluble
Li
soluble
+
Na
soluble
soluble
soluble
soluble
soluble
soluble
soluble
Na
+
soluble
soluble
soluble
soluble
soluble
soluble
soluble
K
insoluble
soluble
soluble
soluble
soluble
slightly
soluble
Mg
soluble
Ca
soluble
Ba
K
Mg
2+
+
2+
soluble
2+
Ca
insoluble
slightly
soluble
soluble
soluble
soluble
2+
Ba
insoluble
insoluble
slightly
2+
soluble
soluble
soluble
soluble
slightly
2+
soluble
Cu
2+
2+
Fe
insoluble
3+
Fe
soluble
soluble
insoluble
soluble
Cu
soluble
soluble
soluble
soluble
insoluble
soluble
Fe
soluble
soluble
soluble
soluble
insoluble
soluble
Fe
soluble
Ag
2+
2+
3+
insoluble
insoluble
insoluble
insoluble
insoluble
2+
insoluble
insoluble
insoluble
soluble
insoluble
insoluble
soluble
Pb
2+
insoluble
soluble
soluble
soluble
soluble
insoluble
soluble
Zn
soluble
soluble
soluble
soluble
insoluble
soluble
Al
soluble
soluble
soluble
soluble
soluble
soluble
NH4
Pb
Al
soluble
+
Ag
Zn
soluble
3+
+
NH4
soluble
2−
CO3
2−
SO4
−
Cl
−
Br
−
I
OH
−
+
2+
2+
3+
+
−
NO3
LearnChemistry
Enhancing learning and teaching
© Royal Society of Chemistry
Tests for gases
Gas
Tests
Observations
Carbon dioxide
Limewater (calcium hydroxide solution)
A white precipitate forms which turns
the limewater cloudy white
Hydrogen
A lighted wooden splint
Gas burns with a popping sound
Oxygen
A glowing wooden splint
Splint relights
Ammonia
Smell
Pungent, choking smell.
Damp red litmus paper
Paper turns blue
Hydrogen chloride gas (from a drop of
concentrated hydrochloric acid on a
glass rod)
A white smoke forms
Colour
Yellow green
Smell
Bleach-like choking smell.
Damp blue litmus paper
Paper turns red, and then bleaches
Damp starch-iodide paper
Paper turns blue-black
Colour
Orange-brown gas
Damp blue litmus paper
Paper turns red, and then slowly
bleaches
Damp starch-iodide paper
Paper turns blue-black
Colour
Violet coloured
Damp starch-iodide paper
Paper turns blue-black
Smell
Pungent smell
Damp blue litmus paper
Paper turns red
Ammonia gas (from a drop of
concentrated ammonia solution on a
glass rod)
A thick white smoke is produced
Blue anhydrous cobalt(II) chloride paper
Paper turns pink
Chlorine
Bromine
Iodine
Hydrogen halides
(chloride, bromide
and iodide)
Water vapour
LearnChemistry
Enhancing learning and teaching
© Royal Society of Chemistry