ES 1 Flashcards
What are halogens?
The elements in group 7 of the periodic table
What are halides?
Group 7 ions or salts
Are all halogens diatomic?
Yes
How do halogen atoms achieve stability?
- gaining an electron from a metal atom
- which forms a halide ion compound
-OR - Sharing an electron from another non-metal atom in a covalently bonded compound
Appearance of F2 at room temp
Pale yellow gas
Appearance of Cl2 at room temp
Green gas
Appearance of Br2 at room temp
Orange liquid
Appearance of I2 at room temp
shiny grey/ black solid
What happens to reactivity down group 7?
Decreases
What happens to MP/BP down group 7?
Increases
Which element in group 7 is the best oxidising agent?
Flourine (top)
What are spectator ions?
Ions that are left out of ionic equations because they are unchanged
What gets reduced in a halogen + halide ion reaction?
The oxidising agent (the halogen)
Half equation for halogen
What is a silver halide?
A precipitate
When are silver halides precipitated?
When a silver ion is added to a solution containing any halide
Ag+(aq) + X-(aq) ->
AgX(s)
What colour is AgCl?
White precipitate
What colour is AgBr?
Cream precipitate
What colour is AgI?
Pale yellow precipitate
Observations when AgNO3 is added to Cl-
White precipitate
Observations when AhNO3 is added to Br-
Cream precipitate
Observations when AhNO3 is added to I-
Yellow precipitate
What happens when you add NH3 to Cl-, Br- or I-?
Cl- dissolves in dilute ammonia
Br- dissolves in concentrated ammonia
I- does not dissolve
What happens to solubility down group 7?
Decreases
What is observed when a sodium halide gas is produced?
Steamy white fumes
What is the trend in reducing ability of halide ions?
Increases down the group
What are the Colours of the elements in vapor state down group 7?
Colourless
Yellow
Orange
Purple
Dark purple
Color of aqueous Cl, Br and I
Chlorine - pale green
Bromine - orange
Iodine - Brown
Colours of Cl, Br and I in cyclohexane
Cl - pale green
Br - red/brown
I - violet/purple
Cl, Br, I appearance and state a RT
Cl - green gas
Br - orange liquid
I - Dark grey solid
How to test for halide ions
Add AgNO3
Ag+ (aq) + Cl-(aq) —> ?
AgCl