Halogens Flashcards
(22 cards)
Oxidising agent
Gain electrons
Reducing agent
Loses electrons
When is oxygen not -2
When with peroxides and compounds with F (-1)
When is hydrogen not +1
In metal hydride egNaH -1
When is chlorine not -1
O or f -2
Covalent
Solid ionic
Leave
Aqueous and ionic
Split
What is electronegativity?
Electronegativity is a measure of the tendency of an atom to attract a pair of electrons in a covalent bond.
How does electronegativity change down a group?
Electronegativity decreases as you go down the group because the halogen atoms get larger and are less strongly attracted towards the electrons.
What is the appearance and state of fluorine?
Very pale yellow gas.
What is the appearance and state of chlorine?
Greenish, reactive gas; in solution very pale green solution (often colourless).
What is the appearance and state of bromine?
Red liquid that gives off dense brown/orange poisonous fumes; in solution: yellow solution.
What is the appearance and state of iodine?
Shiny grey solid that sublimes to purple gas; in solution: brown solution.
HBR
Misty white fumes
SO2
Choking gas
S
Yellow solid
H2S
Rotten egg smell
What is the trend in electronegativity of the halogens down Group VII?
Electronegativity decreases down Group VII.
This is due to the larger atomic radius, which results in a weaker attraction between the nucleus and the outer shell electrons.
What is the trend in boiling temperatures of the halogens down Group VI?
Boiling temperatures increase down Group VI.
This trend is attributed to the increase in molecular size and van der Waals forces.
Oxidising
Electrons on the left
Reducing electrons
Right
