Group 7 Halogens And Redox Flashcards
What is oxidising power
The ability to remove an electron
Oxidising power trend
Cl2> Br2 > I2
The reaction table of halogens for oxidising power
The equation of Cl2 and KCl
There is no reaction
The reaction between Br2 and KCl
There is no reaction
The reaction of KCl and I2
There is no reaction
Why is there no reaction of KCl with the halides
As Br2 and I2 are not a good oxidising powers. They have a bigger atomic radius than Cl2 which mean it cannot remove an electron from the potassium as easily as Cl2 can.
The reaction of KBr and Cl2
The ionic equation of KBr and Cl2
What is the observation we see with the reaction of KBr and Cl2
Orange solution
The reaction of KI and Cl2 including ionic
The observation of KI and Cl2
Brown solution
The reaction of KI and Br2 including ionic
The observation of KI and Br2
Brown solution
Formation of bleach reaction
What is bleach, chemical formula
NaClO
What is bleach used for
Cleaning agent
What is the reaction of bleach called and why
Disproportionation as the chlorine is being oxidised and reduced at the same time
The reaction of Cl2 and H20
The reaction of Cl2 and H20 in UV light
Is Cl2 and H20 reaction a disproportionation reaction
Yes
Why is chlorine used for water treatment even though it is toxic
The benefits outweighs the risks
Reducing power of halides
I2>Br2>Cl2
What is reducing power
The ability to lose an electron
Why is Iodine a good reducing agent
It can easily lose its electron because there is a weaker force of attraction between nucleus and outer electron compared to chlorine
Iodine can easily be oxidised (lose and electron) so it acts as a reducing agent. Something oxidised is a reducing agent and something reduced is an oxidising agent
Reaction of NaCl and H2SO4
Reaction of NaF with H2SO4
Observation of NaCl and H2SO4
Misty white fumes (HCl produced)
Observation of NaF and H2SO4
Misty white fumes (HF produced)
Reaction of NaBr and H2SO4 the two equations
Observation of NaBr and H2SO4
Misty white fumes (HBr produced) Brown fumes (Br2 gas produced)
Reaction of NaI and H2SO4 four reactions
- 8HI + H2SO4 —-> 4I2 +H2S +4H2O
Observation of NaI and H2SO4
Misty white fumes (HI produced)
Black solid/ purple fumes (I2 produced)
Bad egg smell, toxic (H2S produced)
Yellow solid (sulfur produced)
Test for halides
Add HNO3 which is acid that removes unwanted ions such as Carbonate ions
Add Silver Nitrate (AgNO3)
Chloride - white ppt
Bromide - cream ppt
Iodide - yellow ppt
Ionic equation for test of halides
Ionic equation for halide Cl2
Ionic equation for halide test Br2
Ionic equation for halide test Br2
Trend of atomic radius in group 7
Increases
More shells
More shielding
So bigger atoms
Trend of electronegativity in group 7
Decreases
More shells
More shielding
Weaker attraction b/w nucleus and two electrons in covalent bond
Trend of boiling/melting group 7
Increases More electrons Bigger atomic radius More vdw Higher melting and boiling between molecules as halogens are SCM
Ionisation energy trend of group 7
Decreases
More shells
More shielding
Weaker forces of attraction b/w nucleus and electron in outer shell
Displacement in aqueous solutions table of halides in an organic layer
Oxidation state of H2
+1 unless joined to a metal - becomes -1
Oxidation state of O2
-2 always unless joined to H2O2 (hydrogen peroxide) - becomes -1
Table of reactions for reducing power along with equations