P BLOCK (2) 17 and 18 Flashcards
% of iodine in seaweeds
0.5%
chile salt petre contains
0.2% of sodium iodate
atomic and ionic radii in group 17
increases down the group
order of IE in group 17
decreases
order of Electron gain enthalpy
F<Cl>Br>I</Cl>
Order of EN
F>Cl>Br>I
order of MP and BP
increases steadily
why are all halogens colored?
This is due to the absorption of radiation visible region which results in the excitation of outer electrons to a higher energy level. By absorbing different quanta of radiation, they display different colors
fluorine and chlorine are soluble in
water
Bromine and iodine are soluble in
organic solvents: they are sparingly soluble in water
Although the electron gain enthalpy of fluorine is less negative as compared to chlorine, fluorine is a stronger oxidizing agent than chlorine. Why?
low enthalpy of dissociation of F-F bond and high hydration enthalpy of Fâ
oxidation states exhibited by chlorine, bromine, and iodine?
+1, +3, +5, +7
higher oxidation states of chlorine, bromine, and iodine are realized when?
In combination with the small and highly
electronegative fluorine and oxygen atoms
when does chlorine and bromine exhibit +4 and +6
with oxides and oxoacids
fluorine exhibits only
-1 state
which is the strongest oxidizing agent among halogens
fluorine
fluorine reacts with water to form
oxygen
Chlorine and Bromine react with water to form
hydrohalic and hypohalous
most of the reactions of fluorine are
exothermic
oxides of fluorine
OF2 and O2F2
thermally stable oxide of fluorine
OF2
O2F2 oxidises plutonium to
PuF6
the order of stability of oxides of halogens
I>Cl>Br
what is the reason for the higher stability of oxides of iodine?
due to the greater polarising character of I-O bond
