Summary Topic 3 - inorganic - group 7

7
Group
-

, halogens
PROPERTIES DISPLACEMENT BLEACH
REA / ON
> Fluorine / F.) chlorine with cold, dilute
gas
pale yellow They gain sodium
hydroxide solution
-

an
-




gas electron so are an
-


15252ps oxidising agent . 2NaOH+Ch→NaC1O+NaCHHz0
They get less oxidation
state
0 +1 -1
Chlorine (Ch)
> reactive as
they go
-

down the The Bleach is the sodium
green group .




chlorate (1) solution
-




gas
15252ps 353ps Chlorine water
-




+ KBR -
solution
orange CHLORINE AND WATER
> Bromine 43rd formed
red brown KI Brown solution
-
-
+ -




liquid formed Clitthi≥ 21-1++0-+40
-

-




-


15252ps-353ps oxidation
0 +1 -1
3d 454ps
"
Bromine water
state

+ KI -
Brown solution Different reaction in the sun
> Iodine ( Iz) formed
-



Ch 1-1-10 21-1++20-+40
-
grey
solid Iodine solution
,




15252ps€353M
WATER TREATMENT
reaction (brown]
-


no

3d '°454p64d
"




555ps CHLORINE
chlorate (1) ions kill
Boiling Points Ch+2kBr→2kCHBrz bacteria But chlorine
. is
Clz+2Br-→ 24 + Brz toxic
-



.




Increase down
As It is
the
group . van BROMINE harmful if breathed in
der Waals and liquid burn
forces can .




Bn+2kl→2KBr+k
get and
stronger
Ar
as
Brat 21=>212-+12 In the UK it used to
size gets is

bigger Changes
state too
.




IODINE
treat water .




as
gastro
solid .




Iodine is unreactive Water contains lots of
Electronegativity so won't displace
either halide
organic
as
products
dead rats
such

"• down
the
group .
As This means its important
smaller atoms There are other to treat it so the risks
the
are more interesting halide
outweigh benefits .




electronegative reactions