Group 14 Flashcards
Order of IE1:
C>Si>Ge>Pb>Sn
Order of IE2:
C>Si>Ge>Pb>Sn
Density order
Pb>Sn>Ge>C(diamond)>Si>C(graphite)
Mpt:
C>Si>Ge>Pb>Sn
Bpt:
Si>Ge>Sn>Pb
Most stable allotrope of carbon
Graphite
Product of Graphite+ alkaline permanganate:
Mellitic acid + Oxhalic Axid
C6(COOH)6
diamond is a good conductor of ?
heat, not electricity
graphite is a good conductor of____.State reasons.
Electricity, not heat.
Due to weak vanderwaal’s force between the layers.
Good at conducting e due to pi electrons.
TIN:Types
alpha-tin: white
beta tin: grey (like diamond)
alpha and beta tin are in eqbr at T*
132 deg Celsius
No of five membered and six membered rings in fullerenes:
12, n/2 - 10
n= no.of C atoms.
Kernite
Na2B4O7.4H2O
coordination number and mass are ____related:.
Directly
MCl3 on hydrolysis in water forms- write shape,hybr of M
[M(OH)]4- , thd, sp3
AlCl3 in acidic solution forms
[Al(H2O)6]3-, sp3d2
Al+NaOH+H2O—>
2Na[Al(OH)4-+3H2
Al+ HNo3—>
rendered passive due to protective oxide layer.
ONly metal in p block unreactive with halogens
Thallium
Heating borax
1.) Swells up
Borax—>Na metaborate(Na2B4O7)
2) Transparent liq—>Borax bead
Na2B4O7—->NaBo2(metaborate)+B2O3(B anhydride)
Orthoboric acid
H3BO3
1) white, crystalline,soapy
2) sparingly sol. in water, highly soluble in hot water.
3) Formed by adding water and Hcl to borax,
hydrolysis of boron compounds
4) weak monobasic acid
Diborane formation
BF3+LiAlH4–>B2H6+LiF+3AlF3
NaBH4+I2–>B2H6+2NaI+H2
BF3+NaH–>B2H6+Naf
temp=450k
diborane
colourless
highly toxic,
flammable spontaneously in air.
bpt=180k
B2H6+ O2–>B2O3+H20
rxn with lewis base:
forms borane adduct.
REdn of Diborane with AMmonia
B2H6.2NH3,-heat–>inorganic benz B3N3H6
commonality btwn LiAlH4 and NaBH4:
used as reducing agents in organic synthesis
Boron
extremely hard refractory solid
high mpt,low density, very low electrical conductivity
orthoboric acid soln
used as mild antiseptic
14: Halide+water—>
Complex by accepting e- pairs(SiF62-, [GeCl6]2- , Sn(OH)6]2-)
14: Reactivity tow Halogens
MX2, MX4—>Products,which are covalent,
Exception: SnF4, PbF4—>ionic
PbI4 does not exist because enough energy is not released to excite 6s2 e-s
the central atom(C) cannot accommodate the lone pair of electrons from
oxygen atom of water molecule in d orbital. Infer.
CCl4 cannot hydrolyze
CO
colourless,odorless,almost water insoluble gas
powerful reducing agent
oxidizes all metal exides except those of alkaline earth, Al and few transition elements.
Silicones
They have in general high thermal stability,
high dielectric strength and resistance to
oxidation and chemicals.
