tests for cations

• flame tests:

  litium ions produce a crimson flame

  sodium ions produce a yellow flame

  potassium ions produce a lilac flame

  calcium ions produce a red flame

  copper ions produce a green flame
• to complete a flame test you add the substance to a wire loop and put into the Bunsen burner to reveal the flame colour
• some metals form a coloured precipitate with sodium hydroxide

  calcium forms a white precipitate

  copper forms a blue precipitate

  iron(11) forms a green precipitate

  iron(111) forms a brown precipitate

  aluminium forms a white to then colourless precipitate

  magnesium forms a white precipitate