Flame tests
To do a flame test, dip a platinum wire loop in dilute HCL then hold it in a flame, take it out once the flame burns without a colour (this means the platinum is clean). Dip the loop in the sample your testing and put it back in the flame, the colour of the flame will tell you what metal ion is in the substance...
Li+ > burns with a crimson red flame
Na+ > burns with a yellow-orange flame
K+ > burns with a lilac flame
Ca2+ > burns with a brick red flame
Sodium hydroxide solution and identify the ammonia evolved (NH4+)
You can check for ammonia gas using damp red litmus paper (will turn from red to blue is ammonia is present).
To test for ammonium ions in an unknown substance, add a few drops of sodium hydroxide solution to a solution of the unknown substance (in a test tube). Hold a piece of litmus paper near the top of the test tube, if ammonia is being given off, ammonium ions are present in the unknown substance.
Sodium hydroxide
Metal hydroxides are insoluble and precipitate out of solution when formed.
For this test add a few drops of sodium hydroxide solution to a solution the 'mystery compound' (what your testing). This will form an insoluble hydroxide. Some of these hydroxides have characteristic colours, this can be used to tell which metal ions are present in the unknown solution...
Cu2+ > blue
Fe2+ > sluggish green (yes, they are genuinely the words used)
Fe3+ > reddish brown
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