Test for cations Flashcards
What colour does lithium turn in a flame
Crimson
What colour does sodium turn in a flame
Yellow
What colour does potassium turn in a flame
Lilac
What colour does calcium turn in a flame
Orange-red
What colour does copper turn in a flame
Green
What is the method for doing a flame test
You need a clean platinum loop (rub it with fine emery paper + hold it over Bunsen blue flame). Then dip it in the substance then back in the flame. Record the colour change…
Why is flame emotion spectroscopy better than a flame test?
You can only test single metal ions in flame tests whereas in flame emission spectroscopy you can test mixtures too
If your testing unknown metal hydroxides to see colour of precipitate made using NaOH what is formed when the NaOH is added to the metal hydroxide?
An insoluble hydroxide
What colour does calcium hydroxide go when mixed with NaOH?
White
What colour does copper(II) hydroxide go when mixed with NaOH?
Blue
What colour does iron(II) hydroxide go when mixed with NaOH?
Green
What colour does iron(III) hydroxide go when mixed with NaOH?
Brown
What colour does magnesium hydroxide go when mixed with NaOH?
White
What colour does aluminium hydroxide go when mixed with NaOH?
First white the in excess NaOH it redissolves becoming colourless
