Identifying Substances
- Created by: niamh
- Created on: 23-05-10 11:43
Identifying Substances
Flame Tests
Flame Tests are tests that test for positive ions in a metal.
Lilac Flame= Potassium (K+)
Apple Green Flame= Barium (Ba2+)
Red Flame= Lithium (Li+)
Brick Red= Calcium (Ca2+)
Yellow Flame= Sodium (Na+)
Testing positive ions with sodium hydroxide
Positive Ions Symbol ppt colour does it dissolve
Aluminium Al3+ clear-cloudy yes
Calcium Ca2+ clear-white no
Magnesium Mg2+ clear-lilac no
Copper Cu2+ blue no
Iron II Fe2+ green no
Iron III Fe3+ brown no
Testing for Halide Ions
To test for Halide Ions, firstly, you need to acidify the solution with HNO3. Then you add a few drops of silver nitrate and if a precipitate forms, look at its colour to identify your halide...
Halogens Formula Halide Ion Formula Colour of ppt.
Chlorine Cl chloride Cl- white
Bromine Br bromide Br- cloudy/cream
Iodine I iodide I- cloudy yellow
Testing for Sulfate Ions
Sulfate ions are present in sulfuric acid (H2SO4) and copper sulfate (CuSO4). They have the formula SO4-.
To test for sulfate ions, firstly, you acidify the solution with HCl. Next…
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