Slides in this set
Describe state & colour of chlorine, bromine, and iodine at
· Describe Colour of Bromine vapour and iodine vapour
· Describe colours when dissolved in water/Cyclohexane
· Describe and explain what happens when halogens are added
to solutions of halides
· Describe and explain precipitates that form when halide ions
react with silver ions…read more
States and Colour Halogens at
The Halogens exist as diatomic, non-polar molecules, held
by covalent bonds.
The smaller the molecule the less electrons it has, so there
are weaker intramolecular forces acting on it, the easier it is
for the bonds to break apart.
If there are more electrons they can move around the atom
creating temporary dipoles.
So bigger molecules require more energy to separate these
bonds, making the melting and boiling points higher.…read more
The colour of the halogens is due to the absorption of visible
light, resulting in the excitation of the outer electrons, to
higher energy levels.
The amount of energy absorbed from visible depends on the
As the gap between the out shell and centre gets smaller, less
energy is absorbed, a higher wavelength.
The smaller wavelength of light is not absorbed, so it is
emitted, as a darker colour.…read more
Chlorine is a green-yellow gas
at room temperature.
Bromine is a dark
red volatile liquid. It
Evaporates to give an
Iodine is a black solid.
It sublimes to give a purple vapour
on heating…read more