4.8.3 Identification of ions by chemical and spectroscopic means Flashcards
What are flame tests used for?
Flame tests can be used to identify some metal ions (cations).
What flame color does lithium produce?
Lithium compounds result in a crimson flame.
What flame color does sodium produce?
Sodium compounds result in a yellow flame.
What flame color does potassium produce?
Potassium compounds result in a lilac flame.
What flame color does calcium produce?
Calcium compounds result in an orange-red flame.
What flame color does copper produce?
Copper compounds result in a green flame.
What happens if a sample contains a mixture of ions during a flame test?
Some flame colours can be masked.
What can sodium hydroxide solution identify?
Sodium hydroxide solution can be used to identify some metal ions (cations).
What precipitate does aluminium form with sodium hydroxide?
Aluminium forms a white precipitate.
What happens to aluminium hydroxide in excess sodium hydroxide?
Only the aluminium hydroxide precipitate dissolves in excess sodium hydroxide solution.
What precipitate does copper(II) form with sodium hydroxide?
Copper(II) forms a blue precipitate.
What precipitate does iron(II) form with sodium hydroxide?
Iron(II) forms a green precipitate.
What precipitate does iron(III) form with sodium hydroxide?
Iron(III) forms a brown precipitate.
What do carbonates react with to form carbon dioxide?
Carbonates react with dilute acids.
How can carbon dioxide be identified?
Carbon dioxide can be identified with limewater.
What do halide ions produce with silver nitrate solution?
Halide ions produce precipitates with silver nitrate solution.
What color is silver chloride?
Silver chloride is white.
What color is silver bromide?
Silver bromide is cream.
What color is silver iodide?
Silver iodide is yellow.
What do sulfate ions produce with barium chloride solution?
Sulfate ions produce a white precipitate with barium chloride solution.
What are the advantages of instrumental methods?
Instrumental methods are accurate, sensitive and rapid.
What is flame emission spectroscopy used for?
Flame emission spectroscopy is used to analyse metal ions in solutions.
What is produced when a sample is put into a flame during flame emission spectroscopy?
The light given out is passed through a spectroscope, producing a line spectrum.
What can be identified from the line spectrum in flame emission spectroscopy?
The metal ions in the solution and their concentrations can be identified.
