Tests for Ions Flashcards
What colour does lithium give in a flame test?
Crimson.
What colour does sodium give in a flame test?
Yellow.
What colour does potassium give in a flame test?
Lilac.
What colour does calcium give in a flame test?
Red.
What colour does barium give in a flame test?
Green.
How else can you test for metal ions?
Add a few drops of sodium hydroxide solution to produce a coloured insoluble hydroxide.
Why do you add sodium hydroxide solution?
Some metal hydroxides are insoluble and precipitate out of solution when formed.
What colour precipitate does calcium give?
White.
What colour precipitate does copper II give?
Blue.
What colour precipitate does iron II give?
Green.
What colour precipitate does iron III give?
Brown.
What colour precipitate does aluminium give?
White, then colourless (in excess of NaOH).
What colour precipitate does magnesium give?
White.
How do you test for carbonates?
Add a dilute acid and see if it gives of CO2.
How do you test for halide ions?
Add dilute nitric acid (HNO3), then silver nitrate solution (AgNO3).
How does a chloride react to the halide ion test?
Gives a white precipitate of silver chloride.
How does a bromide react to the halide ion test?
Gives a cream precipitate of silver bromide.
How does a iodide react to the halide ion test?
Gives a yellow precipitate of silver iodide.
How do you test for a sulfate ion?
Add dilute hydrochloric acid, followed by barium chloride solution.
What is the result of the sulfate ion test?
A white precipitate of barium sulfate means the original compound was a sulfate.
