Halogen Colours and States
Fluorine is a yellow gas
Chlorine is a green gas
Bromine is a dark orange liquid
Iodine is a dark purple solid
Fluorine is too highly reactive for general use.
Halogens are all simple molecular substances, but some of the Van Der Waals are stronger in some then others.
For example, Fl is smaller and has LESS I.M forces, so it is a gas
Iodine is bigger, and has MORE I.M forces, so it is a solid
Properties: Coloured, Brittle, Insulators, Low Density, React with Group 1
Redox Reactions and Displacement
All Halogens are oxidising agents, and steal electrons from other things. All Alkali metals are oxidised and are the reducing agent.
Halogen = Group 7 element
Halide = Ion of Group 7 element
A more reactive element will obviously displace a less reactive one. The most reactive one is Flourine, and the least is Astatine.
In Hexane, the least reactive element will be the Halogen in the top layer.
A more reactive Halogen will replace a Halide.
Reactivity in the Group
As you go down, the rectivity decreases. This is because they increase in shells. The closer the electrons are to the nucleus, the easier it is to gain those electrons.
Halogens and Acids
Hydrochloric Acid - Hydrogen Chloride
Sulphuric Acid - Hydrogen Sulphate
Nitric Acid - Hydrogen Nitrate
These are all bonded covalently, so: H-Cl
When Dissolved in Water:
They become acids
All hydrogen halides form acids
Acids are ionic substances and break apart in water (dissociation)
Acid definition: Something that releases hydrogen IONS when in water
Reactions of Hydrogen Chloride
HCl can dissolve in water and organic solvents, in water he HCl molecules dissociate and H+ ions cause the soloution to become aciduc.
In organic solvents this doesn't happen and the HCl molecules remain bonded covalently.
Magnesium + Hydrochloric Acid -> Magnesium Chloride = Hydrogen
Mg + 2HCl -> MgCl2 + H2
Calcium Carbonate + Hydrochloric Acid -> Calcium Chloride, Water and Carbon Dioxide
CaCo3 + 2HCl -> CaCl2 + Co2 + H2O
Ionic Equations: Equations with the ions separated, where the ions that undergo no change are removed.
This can be done in steps:
HCl + NaOH -> NaCl + H2O
H+ + Cl- + Na+ + OH- -> Na+ + Cl- + H2O
H+ + OH- -> H2O