Strongly heating copper carbonate in a combustion tube causes it to go black as copper oxide is formed.
Strongly heating zinc carbonate in a combustion tube causes it to go yellow as zinc oxide is formed.
3 of 9
Precipitation of metal ions
Adding sodium hydroxide solution to metal ions forms coloured precipitates (insolube solids)
Add sodium hydroxide solution:
Aluminium - white
Calcium - white
Magnesium - white
Copper - blue
Iron II - green
Iron III - brown
4 of 9
Test for sulfate ions
add dilute hydrochloric acid
add barium chloride solution
white precipitate of barium sulfate is formed
5 of 9
Test for ammonium ions
add sodium hydroxide
ammonia gas given off
damp red litmus paper turns blue
6 of 9
Test for nitrate ions
add aluminium powder (reduces the ions)
add sodium hydroxide solution
ammonia is formed
7 of 9
Test for halide ions
add dilute nitric acid
add silver nitrate solution
precipitates formed:
silver chloride - white
sliver bromide - cream
silver nitride - yellow
8 of 9
Tests for organic compounds
The surfaces of organic compounds will char if they are burned in air. Black marks can be seen on the surface of organic compounds which are burned as carbon is made.
Bromine water can be used to identify whether organic compounds are saturated or unsaturated:
Unsaturated - bromine water goes form brown to colourless
Comments
Report