Halogens Flashcards
What are the group 7 elements?
Chlorine, Florine Iodine and Bromine
~they exist as diatomic
What are the different types of halite ions?
Bromide
Chloride
Iodide
- they exist as single ions with a charge -1
Reactivity series of halogens?
- 2.
3.
*More reactive halogen displaces weaker halogens
What colour is produced when chlorine and KBR reacts? Why does it change this color? Give equation ionic/symbol:
Orange solution - Because bromine is the product in the reaction
{ Cl2 + 2KBR -> Br2 + 2KCL }
ionic: { Cl2 + Br-
- -> Br2 + 2Cl-}
What happens when chlorine and potassium iodine?
Brown solution
What happens when bromine reacts with potassium iodide?
Brown Solution
What is the formation of bleach?
2NaOH + Cl2 –> NaClO + NaCl +
H20
What is bleach used for?
Cleaning
What is a disproportionation reaction?
Is a reaction were same thing is oxidized and reduced
What is the word equation for chlorine and water?
Cl2 + H20 ⇌ HClO (chloric 1 acid) + HCl
Why is chlorine used to treat water?
They benefit outweighs the risk
Why is chlorine used to treat water?
It kills bacteria making it clean preventing spread of disease
What are the disadvantages of using chlorine to treat water?
It is toxic
What is a reducing agent?
a substance that tends to bring about reduction by being oxidized and losing electrons.
Are halides reducing agents?
True/False
True
What happens when halide and sulfuric acid reacts?
metal halide + sulfuric acid —> metal sulfate + hydrogen halide
e.g.
NaCl + H2SO4 –> NaHSO4 + HCl
Why is a reaction between metal halides and sulfuric acid non redox?
This is because there no change in oxidation states
What is released between a reaction with sulfuric acid and metal halide?
Misty White Fumes
What happens during reaction of hydrogen bromine and sulfuric acid?
2HBr + H2SO4 —-> Br2 + SO2 + 2H20
Is hydrogen bromide and sulphric acid a redox reaction?
TRUE/ FALSE
TRUE
What happens when you react hydrogen halide and sulfuric acid?
hydrogen halide + sulfuric acid —> halogen + sulfuric oxide + water
e.g.
2HI + H2SO4 —> I2 + SO2 + 2H20
What happens when you react hydrogen halide and sulfur oxide?
hydrogen halide + sulfur oxide –> hydrogen halide + halogen + water
e.g.
6HI + SO2 –> H2S + 3I2 + 2H20
How do you test for halides?
Add Nitric Acid (HNO3) and Silver Nitrate (AgNO3)
If present:
Chlorine - White precipitate
Iodide - Yellow Precipitate
You can conduct an ammonia (NH3) test:
Chlorine - dissolves in dilute ammonia
Bromine - dissolves in concentrated ionic ammonia
Iodine - does not dissolve in ammonia
What is the the generic symbol equation for halide test?
Ag+ (+) X- —-> AgX
X = Halide
Halogen order according to reducing power
- Iodine (Largest)
- Bromine
- Chlorine (Weakest)
What is the trend in boiling point as you go down group 7? Why?
The boiling point increases - this is because van der walls forces increase due to the increasing size and relative mass of atoms
How does states change as you go down group 7?
gas at the top and solid at the bottom
How does electronegativity change as you go down the group? Why?
As you go down elecronegativity decreases - This is because the larger the atom the distance between positive nucleus and bonding electrons increase know as shielding
What is electronegativty?
Is the ability for an atom to attract electrons towards its’ covalent bond
What happens with reactivity as you go down group 7?
Reactivity decreases
