Chemistry - Atomic structure and the periodic table - Group 0 and testing ions

Question 1

How do you test for ions?

Answer 1

Using a flame test. A cleaned, moistened flame test wire is dipped into a solid sample of the compound. It is then put into the edge of a blue Bunsen flame. The flame colour produced indicates which metal ion is present in the compound.

Question 2

What are the flame colours of Lithium, Sodium, Potassium, Calcium and Barium?

Answer 2

Lithium - Red
Sodium - Yellow-orange
Potassium - Lilac
Calcium - Brick red
Barium - Apple green

Question 3

How do you test for halide ions

Answer 3

Halide ions in solutions are detected using silver nitrate solutions. The test solution is acidified using a few drops of dilute nitric acid, and then a few drops of silver nitrate solution are added. Different coloured silver halide precipitates form, depending on the halide ions present.

Question 4

What colour precipitate of silver chloride does Chloride, Bromide and Iodide produce?

Answer 4

-Chloride ions give a white precipitate of silver chloride
-Bromide ions give a cream precipitate of silver bromide
-Iodide ions give a yellow precipitate of silver iodide

Question 5

Why don’t group 0 gases need to lose or gain ions?

Answer 5

They all have a full outer electron shell which means they are already stable.

Question 6

What properties do group 0 gases have in common?

Answer 6

-They are non-metals
-They are very unreactive gases
-They are colourless
-They exist as single atoms (they are monatomic)

Question 7

What are the uses of helium, neon and argon.

Answer 7

-Helium - Party balloons, weather balloons, airships
-Neon - Red neon signs, lasers
-Argon - Shielding gas for welding, surrounding the filament in an old-fashioned lightbulb