Group 1 and 2 tests Flashcards
(20 cards)
Lithium ions
Red
Sodium ions
Orange/yellow
Potassium ions
Lilac
Rubidium ions
Red
Caesium ions
Blue
Calcium ions
Brick red
Strontium ions
Crimson
Barium ions
Green
Step 1 of carrying out a flame test
Sterilise a nichrome wire in concentrated HCl and hold over hottest part of the Bunsen burner flame
Step 2 of carrying out a flame test
Dip the wire in HCl then in the metal compound you are testing so it sticks to the wire
Step 3 of carrying out a flame test
Hold this in hottest part of the flame and observe the colour produced
What happens when an ion absorbs energy from the Bunsen burner?
Caused electrons to move onto higher energy levels because they are in excited state
What happens when an electron falls back to its ground state (lower energy level)?
It releases the energy it absorbed in the form of a wavelength which is visible light
What determines the colour observed in a flame test?
The wavelength of light wave the electron omitted
How to test for Mg2+?
Place compound in water
If an insoluble white pot formed = magnesium ions
If oxygen gas is given off on heating a metal compound
Group 1 nitrate except lithium nitrate
If nitrogen dioxide gas is given off on heating metal compound
Group 2 nitrate
Lithium nitrate
If carbon dioxide gas is given off on heating a metal compound
Group 2 carbonate
Lithium carbonate
Do group 1 compounds form a precipitate when aqueous NaOH is added?
No forms group 1 metal hydroxide solution
Fully soluble
Do group 2 compounds form a precipitate when aqueous NaOH is added?
Forms a white precipitate that is more soluble down the group
