gr 16 Flashcards
typical non metals
o
s
metalloid behaviour
Se Te
halflife of TE
13.8 days
who all r octa atomic
S
Se
Te
most abundant element in earths crust
O
Po is found as
decay product of Ur and thorium
hydride with highest bp
h2o
hydride w least bp
h2s
only liquid hydride
h2o rest are gas
B A trend among hydrides
decrease down the group
B E trend among hydrides
decrease dtg
acidity among hydride trend
increase dtg
H2s pptys
colorless
poisonous
rotteen egg smell
prep of h2s
kips reaction
hydrolysis of Al2S3
hydrolysis of thioacetamide
prep of pure h2s
antimony + dil. HCl
what is kips rxn
FeS + h2so4 = h2s + feso4
bond ange between h2s-
92.5
state of
SO2
seo2
teo2
SO2 - gas
seo2 - solids
teo2 - solids
so3
seo3
teo3
so3 - gas / solid
seo3 cyclic tetramer
teo3 3d covalent giant molecule
why seo2 and teo2 solids
polymeric solids
are all bonds in so3 same
no
2- p āā - dāā
1- pāā-pāā
how many forms of so3 solid and what are they
3 , alpha beta gama
which two forms of so3 are interconvertible
alpha and beta
which form is most stable and why
gama becs cyclic tetraer
structure of seo3
and teo3
seo3- cyclic tetramer
teo3- o attached to edge octahedral atoms
stability of halides
decrease from f- i
why is sf6 inert
its resistant to hydrolysis gasesous insulators
all tetrahalides are
see saw shaped
how is sf4 prepared
flurinating scl2 with naf in presence of MeCN
best fluorinating agent
sf4
uses of sf4
convert
cooh- cf3
co- cf2
po- pf2
which dihalide doesnt exist and why
Se becs thermodynamically unstable
what is s2cl2 and structure
monohalide, non linear, dimer
what is SE2cl2
dimer non linear monohalie
uses of s2cl2
volacanisation of rubber
o2 - para or di
para
completely absorbed by
alkaline pyrogallol
ppty of pyro gallol
biscuit colored solid
prep of o2
a. heating oxygen rich source like chlorate or nitrates
in presence of MnO2 as catalyst
b. moderate heating of heavy metal oxide
i.e, heating of Hgo or Ago
c. burning of mixed oxides
d. decomposition of h2o2
e. electrolysis of acidified water
f. brins process- decomposition of Bao2 in steps
g. heating bleachin powder w Co saltwhat happens when berthelot salt is heated
gives o2
kclo3 is berthelot salt - oxygen rich
pptys of o2
easily liquified- pale blue colored
has 2 named rxns-
a. ostwalds process- manufacture of NO
b. deacons process- manufacture of cl2 by ( hcl + o2)
uses of o2
life sustenance
produce welding flame ( o2 + actelene)
for rocket propellants
combustion fuels
what are sub oxides
E āEā-O bond containing oxides
polyxide
% of oxy is higher - peroxide or superoxide
nature of transition metal oxides
acidic
nature og na2o mgo
basic
o3 pptys
diamag pale blue gas solid fishy smell deep blue liquid, violet black solid act as oxidant only high +ve rp
why is o3 thermodynamically unstable
it spontaneously decomposes to formm o2
cautions of high conc o3
explosive
inhalation of o3 causes
nausea dizziness
soluble in
non polar liquid- turpentine cinnamon oil ccl4
INSOLUBLE IN WATER
is it denser than air
yes 1.67 times
lab prep of o3
silent electric discharge thru dry oxygen
endothermic, decrease in volume
to prevent sparkles , carried out in siemens ozoniser
to increase conc pass thru batterised ozoniser like BRODIES OZONISER
reaction of o3
PbS + o3 = pbso4 (white) + o2
depleltion of o3 layer by reacting with NO and forming o2 and no2
estimate o3 by idometry - 1 mol { ph = 9.2 by borate buffer}
