Tests for Ions.
How can Ions be Detected?
Ions
can be divided into positive ions and negative ions.
Positive ions are metal ions or ammonium.
Negative ions are non-metal
ions.
Positive ions can be
detected in a solid
using a flame test (if the metal gives a coloured flame)
or in solution
with sodium hydroxide.
Negative
ions can be detected in
solution by using
1. a dilute acid for carbonate and sulfite
2. dilute hydrochloric acid and
barium chloride for sulfate
3. dilute nitric acid and
silver nitrate for chloride, bromide and iodide
4. aluminium powder and sodium
hydroxide solution for nitrate.
Some carbonates show a
colour change during thermal
decomposition.
Hydrogen ions and hydroxide ions can
be detected using acid/base indicators.
There are a number of
instrumental methods for
the detection of ions.
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