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Water - Solubility - Ions

Flame Tests.

Some metal ions can be identified by the colour of their flame
during a flame test. Metals or metal salts
having a coloured flame are used in fireworks.

A flame test uses a piece of nichrome wire.
You dip the end of the wire in concentrated hydrochloric acid
and then hold it in a hot bunsen flame. If the wire is
not contaminated, the colour of the flame will not change.

If the flame changes colour, dip the wire in
concentrated hydrochloric acid again and return
it to the bunsen flame. Repeat this procedure
until the wire shows no change of colour in the flame.

Now dip the end of the wire in concentrated hydrochloric acid
and put the wire into the solid which you are
using for the flame test.
A small amount of the metal chloride will form on the wire.
Hold the wire in the flame and see what colour is produced.
The table below shows
which colours are produced by some metal ions.

Metal Ion Flame Colour
Lithium   Li+ Red
Sodium   Na+ Yellow/Orange
Potassium   K+ Lilac
Calcium   Ca2+ Brick Red
Barium   Ba2+ Light Green
Copper   Cu2+ Blue/Green

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