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Elemente i combinaii chimice
Blocul p
Metale
Nemetale
Proprietati fizice si chimice
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Blocul p
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Grupa 13. Legturi chimice
! "ombina#ii cu legturi covalente M$3%M & B' (l' )*:combinaii deficiente n electroni+ (ceste combina#ii nu suntde ,apt stabile iar stabili-area lor are loc prin acceptarea deelectroni ,ie de la atomi din interiorul aceleiai molecule ,iedin eteriorul acesteia. 0ac se primesc electroni de laatomii unor molecule de acelai ,el' re-ult dimeri sau
polimeri' iar dac acetia provin de la molecule strine aparcompuii donor-acceptor nite combina#ii compleeadeseori av2nd structuri tetraedrice sau octaedrice.
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Borul! Structura cristalin: structur av2nd la ba- icosaedrul' o
,igur geometric cu 1 v2r,uri i 4 de ,e#e+ apte modi,ica#iialotropice ale acestuia' 5n toate regsinduse icosaedrelegate 5ntre ele 5n alte moduri+
! Stare natural: "lar6: 781439' totui se gsete concentrat pre-en#a sa este esen#ial pentru de-voltarea plantelor+
minerale: boraxul' NaB:;
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(luminiul
! Structura cristalin: metalic' heagonalcompact+! Stare natural: "lar6:
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ob#inere alumina
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Borul S (luminiul proprietati chimice
A
X2
O2
N2
S
C
Oxizi
HCl
alcalii
AlX3
Al2O3
AlN
Al2S
3
Al4C3
Metale(Aluminotermie)
lCl3+ H2
[Al(OH)4(H2O)2!+ H2lO2! + H2 "au
B
X2
O2
N2
S
C
#4O$%
HNO3
alcalii
HBO2! + H2
H3BO3+ NO
BX3
B2O3
BN
B2S3
B4C
#4+B2O3
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Borul S (luminiul proprietati ,i-ice#ro&rietate B Al
'#($) e* 3% ,-,
'#(2) e* 2,$, $2
'#(3) e* 3.-2 244
/oM3+0M
(*) !%.3 !$1.
(cm!3
) 24 2.
#t (oC) 23%% 11%
#5 (oC) 2,,% 2,%%
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Borul S (luminiul utili-ri
!Borul: servete ca element de aliere 5n o#eluri imprim2ndacestora o deosebit re-isten# la impact+ av2nd o sec#iunee,icace mare pentru neutroni' servete la con,ec#ionareabarelor de control a reactoarelor nucleare+ con,er metalelorcu care se alia- duritate i re-isten# la coro-iune+ borurile
metalice sunt materiale cu propriet#i mecanice i chimice ,.bune+ se utili-ea- 5n tehnica nuclear+! Aluminiul: dup ,ier' cel mai ,olosit metal+ ie,tin' uor'
re-istent la coro-iune' conserv 5n timp propriet#ile' sepoate trage 5n ,oi i ,ire' bun conductivitate termic+ la
aceeai mas' conduce curentul mai bine dec2t oricare altmetal+! 0in aluminiu se con,ec#ionea- aliaTe uoare S re-istente
mecanic ,olosite 5n construc#ii S maini. (luminiul se alia-bine cu ,ierul' siliciul' magne-iul' cuprul i -incul
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Borul S (luminiul combina#ii complee
CH O
CH O O CH
O CHB(!)
! Borulare de a da combina#ii tetracovalente+ o serie decombina#ii dihidroilice sau polihidroilice ca pirocatechina'glicerina sau manitolul %> ;=*+ Aluminiul,ormea-compleci cu Udicetone sau cu Vhidroichinoleina+
! bor-azot: Borazolul' B3N3=> denumit benzen anorganic;3LiB= C 3N="l ? B3N3=> C 3Li"l C 1=
! Azotura de bor' BN: 1V44P"' V7.444 atm reactoare nucleare'cptuirea camerelor de ardere a rachetelor S avioanelor'
material dielectric
(l W Ga
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Ga' Hn' Jl proprietati chimice
7 8 9a 'n
X2
NH3
7X3
7N
O2H2SO
472(SO4)3
S
72S3
72O3
7 8 9a 'n
2 32
2 3
2 4
2 4 + 2
2
+ 2
a e
2
3
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Ga' Hn' Jl propriet#i ,i-ice
Qroprietate Ga Hn JlH.Q.%1*' eE >.4 7.V >.1
H.Q.%*' eE 4. 1V.V 4.3
H.Q.%3*' eE 34.>
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Ga' Hn' Jl Xtili-ri
!Galiul: ob#inerea unor aliaTe cu puncte de topire Toaseutili-ate 5n calitate de siguran#e electrice. iind netoic i cupunct de topire cobor2t' acesta mai servete ca agent detrans,er termic 5n schimbtoarele de cldur din industrianuclear' drept lichid termometric pentru temperaturi mari i
ca miTloc de etanare 5n tehnica vidului. 0e asemeneaservete la ob#inerea unor compui Ga(s sau GaQsemiconductori importan#i.
! Indiul: ob#inerea de aliaTe pentru lagre sau cu-ine#i %autolubri,iante de eemplu HnQb*' a unor oglin-i cu mare putere
de re,leie %similare celor din (g dar mai re-istente lacoro-iune*.! aliul: ob#inerea unor sticle speciale' mrind indicele de
re,rac#ie a sticlei sau pentru ,abricarea unor catali-atori.
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Grupa 1. "arbon S Riliciue le=tur=
?@mol!$
O"eraii
C D C 34 Formeaz= catene (lanuri) 5oarte luni
Si D Si 2-. Formeaz= &uine lanuri "curte
C D O 343 'n oxizi Ei caronai
Si D O 31- 'n "ilicai cu "tructuri ariate 5oarte"taili
C D H 4$3 'n i>rocaruri lanuri 5oarte luni
Si D H 3$ 'n "ilani lanuri "curte
C D Cl 32 !
Si D Cl 3$ !
C D Si 3%$ Foarte "tail=
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Grupa 1. Qroprietati ,i-ice7lement 6aze
coalente (nm)
St=ri >e
oxi>are
7lectroneatiit
(#aulin)
#t
G
#5
G
C .. !'* '' '* 2,, 3%% 43%%
Si $$. ! '* '* $-% $1. 3$.3
9e $22 ! '* '' '* 2%$ $2$$ 3%-3
Sn $4% ! '* '' '* $-1 ,%, 2.,
# $41 ! '* '' '* 233 1%$ 2%22
Qropriet#i ,i-ice i chimice
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! (ctivation Ynergies' Ynvironmental ate' HsoelectricQoint'(ctivity "oe,,icients' YZuilibrium "onstants' Ainetic 0ata'(dsorption and (dsorption "oe,,icients' Ypansion "oe,,icient'Lattice Ynergies'(ntoine "oe,,icients and "onstants'
Yplosive Qroperties' Log Q'(tomic Mass "onstant'Yposure Limits' Luminescence'(tomic [adius'Ytinction "oe,,icient' Melting Qoint'(vogadro\s "onstant'lammability' Molar(bsorptivity' Bioconcentrationactor'lash Qoint' Molecular ]eight' Biodegradation' ree Ynergy'
NQ( "hemical =a-ardLabelling' Bohr [adius' ree-ing Qoint' ;ctanol/]ater Qartition "oe,,icient' Boiling Qoint'riction "oe,,icient' ;ptical [otation' Bolt-mann"onstant'undamental Qhysical "onstants';idation[eduction Qotentials' Bond Ynergies' Gactors'
;idation Rtates' Bond Lengths/Bond (ngles' Gas Law';-one 0epletion Qotential' "ompressibility' Gibbs ree Ynergy' Qartition "oe,,icients' "onductivity' =al, Li,e' Qhase 0iagrams' "onversion ,actors' =a-ard [atings' "ode and [eactions'Qhysical Qroperties' General' "orrosion' =eat "apacity' pA'
"ritical Qroperties' =eat o, "ombustion' Qroton (,,inity
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"rystal Rtructure and Rpace Groups' =eat o, 0ilution' [adii'0ebye=uc6el"oe,,icients' =eat o, ormation' [ate "oe,,icients' 0ecomposition [ate' =eat o, usion' [ate "onstants'0egradation' =eat o, =ydration' [e,ractive Hnde' 0ensity'
=eat o, Honi-ation' Rolubility' 0ielectric "onstant' =eat o, Miing'Rpace Group' 0i,,usion %Molecular*' =eat o, Neutrali-ation'Rpeci,ic Gravity' 0ipole Moment' =eat o, Qolymeri-ation'Rpeci,ic =eat' 0issociation "onstant' =eat o, [eaction'Rpeci,ic [otation' 0istribution "oe,,icient' =eat o, Rolution'
Rtability "onstants' Ylectrical "onductivity' =eat o, Rublimation'Rur,ace Jension' Ylectrical[esistivity' =eat o, Jrans,ormation'Jensile Rtrength' Ylectrode Qotentials' =eat o, Jransition'Jhermal "onductivity' Ylectron (,,inity' =eat o, Eapori-ation'Jhermal 0i,,usivity' Ylectron Binding Ynergies'=enry\s Law "onstants and "oe,,icients' Jhermal Ypansion'Ylectron "on,iguration' Hnternuclear0istance'Jhermodynamic Qroperties' Ylectronegativity'Honi-ation "onstant' Eapor Qressure' Ynthalpy' Honi-ation Ynergy' Eirial"oe,,icient' Ynthalpy o,...' Honi-ation =eat' Eiscosity'Yntropy' Honi-ation Qotential' ^oung\s Modulus
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u/science/property.htmhttp://www.library.vanderbilt.edu/science/property.htmhttp://www.library.vanderbilt.edu/science/property.htmhttp://www.library.vanderbilt.edu/science/property.htmhttp://www.library.vanderbilt.edu/science/property.htmhttp://www.library.vanderbilt.edu/science/property.htmhttp://www.library.vanderbilt.edu/science/property.htmhttp://www.library.vanderbilt.edu/science/property.htmhttp://www.library.vanderbilt.edu/science/property.htmhttp://www.library.vanderbilt.edu/science/property.htmhttp://www.library.vanderbilt.edu/science/property.htmhttp://www.library.vanderbilt.edu/science/property.htmhttp://www.library.vanderbilt.edu/science/property.htmhttp://www.library.vanderbilt.edu/science/property.htmhttp://www.library.vanderbilt.edu/science/property.htmhttp://www.library.vanderbilt.edu/science/property.htmhttp://www.library.vanderbilt.edu/science/property.htmhttp://www.library.vanderbilt.edu/science/property.htmhttp://www.library.vanderbilt.edu/science/property.htmhttp://www.library.vanderbilt.edu/science/property.htmhttp://www.library.vanderbilt.edu/science/property.htmhttp://www.library.vanderbilt.edu/science/property.htmhttp://www.library.vanderbilt.edu/science/property.htmhttp://www.library.vanderbilt.edu/science/property.htmhttp://www.library.vanderbilt.edu/science/property.htmhttp://www.library.vanderbilt.edu/science/property.htmhttp://www.library.vanderbilt.edu/science/property.htmhttp://www.library.vanderbilt.edu/science/property.htm 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0uritate! Hn materials science' hardnessis the characteristic o, a
solidmaterial epressing its resistance to permanent
de,ormation. Indentation hardness! Hn mineralo"#'hardnesscommonly re,ers to a material\s ability to penetrateso,ter materials. (n obTect made o, a hardmaterial willscratch an obTect made o, a softermaterial Scratchhardness!(lso 6nown as dynamicor absolute hardness'rebound hardness measures the height o, rebound o, anindenter dropped onto a material using an instrument 6nownas a scleroscope $ebound% d#namic or absolutehardness! Sclerometer a mineralogist\s %usually*instrument used to measure the hardness o, materials. Jheinstrument is designed to determine the degree o, hardnesso, a given mineral by applying pressure on a movingdiamond point until a _scratch_ has occurred. Methods o,hardness testing: Jurner\s Rclerometer+ Rhore\s
Rcleroscope+ Brinell\s Jest+ Aeep\s Jest.
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Rcari de duritate! BrinellB !" #$ %&'% (arts )* +* ,* and . +''&* /etallic
materials - Brinell hardness test! &noop#$ && (arts )* +* ,* and . +''&* /etallic materials
- 0noop hardness test
! $oc'(ellB !" #$ %&'1 (arts )* +* and ,. +''&* /etallicmaterials - 2ock3ell hardness test 4scales A* B* 5* 6* !* 7* 8*9* 0* "* :
! )ic'ersB !" #$ %&'< (arts )* +* and ,. +''&* /etallicmaterials - =ickers hardness test
! *ohsA scale to measure hardness 3as de>ised by Austrian
mineralogist 7rederick 47riedrich /ohs in )1++! BarcolA:/ 6+&1,-?& e).+'')* tandard :est /ethod for
#ndentation 9ardness of 2igid (lastics by /eans of a Barcol#mpressor
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0uritate relativa vs. absoluta
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Materiale avansate ultradure! Hn 1OVO' Marvin "ohen and his graduate student (my Liu
%then at X" Ber6eley* devised a theoretical model to predicta crystal\s sti,,ness. "ohen\s model clearly indicated that acarbon nitride crystal should be sti,,er %and possibly harder*than diamond. Jhe race was on to obtain the stu,, in
crystalline ,orm and measure its properties. Rome earlye,,orts by the team o, ^ip]ah "hung %NorthwesternXniversity* resulted in a layered composite o, titanium nitrideand carbon nitride %a socalled superlattice* which was'surprisingly' almost as hard as diamond. Ystimates ,romproposed molecular structure indicate the hardness o, betacarbon nitrideshould also be greater than diamond. Jhismaterial has not yet been success,ully synthesi-ed.
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Materiale avansate ultradure! [ecently %ebruary 44* a new 6ind o, synthetic diamond
was ,ound to be at least 749 harder than natural diamond.Jhis was obtained at the "arnegie Hnstitution`s GeophysicalLaboratory %]ashington' 0"* by submitting to etremetemperatures and pressures %444P"' 7< GQa* crystalssynthesi-ed Kmuch ,aster than be,ore by a new chemical
vapor deposition %+),* process.! Hn the 0ecember th' 447 issue o, Jhe erusalem Qost'
Qro,essors Yli (ltus' =arold Basch and Rhmaryahu =o-' withdoctoral student Lior Ht-ha6i report the discovery o, Pol##ne'
a material 4 times harder than diamond. Ht is a superhardmolecular rod' comprised o, acetylene units.! ltrahard fullerite .+/01is a ,orm o, carbon ,ound to be
harder than diamond' and which can be used to create evenharder materials' such as aggregated diamond nanorods.
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Materiale avansate ultradure! A""re"ated diamond nanorods' or (0N[s' are an
allotrope o, carbon believed to be the least compressiblematerial 6nown to human6ind' as measured by its isothermalbul6 modulus+ aggregated diamond nanorods have amodulus o, O1 gigapascals %GQa*' while a conventionaldiamond has a modulus o, GQa %hardness 1.11 timesthan diamond*. (0N[s are also 4.39 denser than regulardiamond. Jhe (0N[ material is also harder than type HHadiamond and ultrahard ,ullerite. ( process to produce thesubstance was discovered by physicists in Germany' led byNatalia 0ubrovins6aia' at the Xniversity o, Bayreuth in 2003.
(0N[s are made by compressing the ">4 molecules to 4GQa' while at the same time heating to 744 Aelvin' using auniZue 7444 metric tonne multianvil press. Jhe resultingsubstance is a series o, interconnected diamond nanorods'with diameters o, between 7 and 4 nanometres and lengths
o, around 1 micrometre each.
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"ompararea duritatii! ( #pe IIa diamond%111* has a hardness value o, 1>
gigapascals %GQa* when scratched with an ultrahardfulleritetip. ( #pe IIa diamond%111* has a hardness valueo, 317 GQa when scratched with a diamondtip+ this leadsto hypothetically in,lated values.
! ltrahard fulleritehas a hardness value o, 314 GQa' though
the actual value may range 4 GQa' since testing doneusing an ultrahard fulleritetip on ultrahard ,ullerite will leadto' li6e diamond on diamond' distorted values.
! Ht is thought that beta carbon nitridewill have a hardnessvalue' i, harder than diamond' less than that o, ultrahard
,ullerite.! ]e notice there are still hundreds o, Tewellery websites out
there still saying that diamond is the hardest substance.he# are all (ron"' and out of date b# man# #ears' whichdoes not surprise us at all.
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ulerena ">4
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ulerena "
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">4 cristali-ata c,c
D">4ullerene at
173 A' ">4crystalli-es in a,ace centeredcubic
arrangementF =.B.Burgi' Y.Blanc'
0.Rchwar-enbach' Rheng-hong
Liu' ^ingTie Lu'M.M.Aappes'.(.Hbers' (ngew."hem.Hnt.Yd.Yngl.' 31' p.>4' 1OO
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%eta"4,ullerene at13A
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eoliti
! eolites are microporous crystalline solids with wellde,ined structures.Generally they contain silicon' aluminium and oygen in their ,ramewor6
and cations' water and/or other molecules wthin their pores. Many occurnaturally as minerals' and are etensively mined in many parts o, theworld. ;thers are synthetic' and are made commercially ,or speci,ic uses'or produced by research scientists trying to understand more about theirchemistry.
! Because o, their uniZue porous properties' -eolites are used in a varietyo, applications with a global mar6et o, several milliion tonnes per annum.Hn the western world' maTor uses are in petrochemical crac6ing' ionechange %water so,tening and puri,ication*' and in the separation andremoval o, gases and solvents. ;ther applications are in agriculture'animal husbandry and construction. Jhey are o,ten also re,erred to asmolecular sie>es.
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! eolites have the ability to act as catal#sts,or chemicalreactions which ta6e place within the internal cavities. (nimportant class o, reactions is that catalysed by hydrogenechanged -eolites' whose ,ramewor6bound protons give rise
to very high acidity. Jhis is eploited in many organic reactions'including crude oil crac6ing' isomerisation and ,uel synthesis.eolites can also serve as oidation or reduction catalysts'o,ten a,ter metals have been introduced into the ,ramewor6.Yamples are the use o, titanium RM7 in the production o,
caprolactam' and copper -eolites in N; decomposition.
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eoliti (dsorptie si Reparare
! Jhe shapeselective properties o, -eolites are also the basis,or their use in molecular adsorption. Jhe ability pre,erentiallyto adsorb certain molecules' while ecluding others' hasopened up a wide range o, molecular sieving applications.Rometimes it is simply a matter o, the si-e and shape o, porescontrolling access into the -eolite. Hn other cases di,,erenttypes o, molecule enter the -eolite' but some di,,use throughthe channels more Zuic6ly' leaving others stuc6 behind' as inthe puri,ication o,paraylene by silicalite.
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eoliti Rchimbatori de ioni
! Jhe looselybound nature
o, etra,ramewor6 metalions %such as in -eolite 4aA- fi"!* means that they areo,ten readily echanged ,or
other types o, metal whenin aZueous solution.
! Jhis is eploited in a maTor way in water so,tening' where al6ali
metals such as sodium or potassium pre,er to echange out o,the -eolite' being replaced by the _hard_ calcium andmagnesium ions ,rom the water. Many commercial washingpowders thus contain substantial amounts o, -eolite."ommercial waste water containing heavy metals' and nucleare,,luents containing radioactive isotopes can also be cleaned
up using such -eolites.
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eoliti! 8rupa zeoliilorare o structur ceva mai a,2nat cu goluri
micronice. 0enumirea acestora 5nseamn 5n limba greac
Fpietre care ,ierb_ pentru c la 5ncl-ire eliberea- apare#inut 5n pori' datorit unor ,or#e super,iciale' sub ,orm devapori. Xn repre-entant din aceast grup este natrolitacu,ormula Na(lRi3;V8=; sau oidic:
Na;8(l;38>Ri;8=;. n analcit' un alt aluminosilicattridimensional 1/3 din atomii de siliciu devin (l. n acest ca-%Ri;*3 devine (lRi;> iar analcitul se scrieNa(lRi;>8=;. (pa este ap de hidratare i se datorea-aluminiului care sa v-ut c pre-int o puternic tendin# dea da hidra#i
! B5+ Boron +arbideis one o, the hardest materials 6nown'ran6ing thirdbehind diamond and cubic boron nitride. Ht is
the hardest material produced in tonnage Zuantities.
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Riliconi! Runt compui organo-silicicicare con#in legturi Ri". "ele
mai lungi lan#uri de atomi de siliciu se reali-ea- 5ntruncompus ,luorurat' Ri1>3. Qrin hidroli- 5n condi#ii binecontrolate' se ob#in compui ciclici cu 3''7 sau > atomi de Ri%ciclosiloani*
O
Si
O
SiO
Si
Me
Me
Me
Me
Me Me
Si O Si
OSi O Si
O
Me
Me
Me
Me
Me
Me
Me
Me
6 Si
O
O
O Si
6
O
O
Si
6
O O Si
6
O Si
6
O
O
Rili i
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Riliconi! Riliconii sunt compui cu propriet#i speciale' ,oarte apreciate
5n tehnic' dei au pre# de cost ,oarte ridicat. a# de
polimerii organici' au o stabilitate termic mult mai ridicatceea ce ,ace s poat ,i utili-a#i 5n condi#ii de temperaturiridicate. (u o mare inerie chimic: sunt re-isten#i la oidare'la ac#iunea apei i a numeroilor agen#i chimici. [e-isten#achimic ,oarte ridicat se datorea- stabilit#ii legturilor Ri
;Ri; i Ri". Runt foarte buni izolatori electrici' mai alesc prin descompunere' nu dau natere la materialeconductoare' cum se 5nt2mpl 5n ca-ul unor polimeriorganici. unt hidrofobi calitate uneori deosebit de apreciat.
! (olimerii liniari' ,orma#i din lan#uri cu 4744 unit#i' sunt
,lui-i' cunoscu#i ca uleiuri siliconice %cu raportul [/Ri*careau vaste 5ntrebuin#ri ca lubri,ian#i' 5n special 5n tehnicavidului' datorit ,aptului c au presiune de vapori i tensiunesuper,icial ,oarte sc-ut. Re pot utili-a de asemenea latemperaturi ridicate. Xleiurile siliconice utili-ate 5n tehnicrepre-int >39 din totalul produselor siliconice.
Rili i
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Riliconi! Xleiurile siliconice utili-ate 5n tehnic repre-int >39 din totalul
produselor siliconice. Re utili-ea- ca dielectrici 5n trans,ormatori de
5nalt tensiune' ca ,luide hidraulice' la impermeabili-area construc#iilor' amainilor' 5n industria 5ncl#mintei. 0e asemenea se utili-ea- caadausuri reductoare de spum %datorit tensiunii super,iciale sc-ute*
5n industria tetil' alimentar etc.! "reterea lungimii lan#urilor duce la creterea v2sco-it#ii substan#elor.
Qe aceast cale se pot sinteti-a uleiuri siliconice i unsori siliconice* apunctului de ,ierbere. (st,el se ob#in uleiuri v2scoase i care deasemenea au importante utili-ri ca lubre,ian#i.
! (olimerii siliconici,orma#i din lan#uri ce con#in >444>44444 unit#i %atomide Ri*' stau la ba-a cauciucurilor siliconice%cu [/Ri *!(cestea seamestec cu o umplutur ,in divi-at %de eemplu Ri; sau gra,it*.Ylasticitatea cauciucurilor siliconice este ceva mai sc-ut dec2t acauciucurilor butadienice %polimeri organici*' dar acestea 5i pstrea-elasticitatea 5ntrun interval ,oarte larg de temperatur %5ntre O4f iC74f"*. "auciucurile siliconice pot ,i vulcani-ate i au bune propriet#ide i-olatori electrici.
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Riliconi! 2inile siliconice%cu [/Ri* sunt polimeri rigi-i care
seamn cu bachelita. Re pot ob#ine prin hidroli-a unuiamestec de ">=7Ri"l3 C %">=7*Ri"l 5n toluen. (ure-isten# chimic i termic ridicat. Re utili-ea- cai-olatori electrici 5n electrotehnic' deseori amesteca#i cu
,ibre de sticl pentru creterea re-isten#ei' la 5ncapsulareacircuitelor integrate' ca re-isten#e etc.
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Ge' Rn' Qb proprietati chimice
9eO2
SnO2#AO
X2
S
#A(C2H,)49eCl4 SnCl4 H2[#ACl4
MS2MS
MX4 MX2
O2
H2
HNO3
MH4
9eO2 H2SnO3 #A(NO3)2
9e Sn #A
C2H,Cl
HCl
al
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4% P% As% Sb% Bi
! Grupa 17 este important mai
ales prin cele dou @elementeale >ieii@a-otul %N* i ,os,orul%Q*' primul ,iind un elementindispensabil pentru c intr 5ncompo-i#ia proteinelor %i
en-imelor* dar este icomponent al unor eplo-ivisau a unor materiale plastice'importante pentru tehnic.
os,orul' 5mpreun cu a-otul'este un alt element esen#ialgsit at2t 5n #esuturile nervoasec2t i 5n oase respectiv
citoplasma celulei.
al
neruro"u
"ticlo"
run (#2)
os,or %Q*
[ed phosphorus consists o,Q bonded in a randomstructure. Blac6 phosphorus isless reactive that whitephosphorus. Ht consists o, anetwor6 o, phosphorus atomswith each atom attached tothree others ultimately ,orminga double layer structure. ]hitephosphorus has molecules o,the ,orm Q.
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Repararea a-otului prin distilare;b#inerea azotului se ,ace prinprocedeul
5laude' ba-at pe condensri i detentesuccesive ale aerului ceea ce determin oscdere su,icient a temperaturii strictnecesare liche,ierii acestuia. (erul liche,iateste apoi trimis 5n nite coloane de recti,icare
5n care este introdus 5n -ona de miTloc aacestora iar la partea superioar' o parte dina-otul lichid' ob#inut prin condensare %p.,. &1O7'VP"*' curge de sus 5n Tos' pe nite talere'
5n timp ce ga-ul %aerul evaporat* urcde Tos 5n sus. (st,el sus se separ lichidul
cu temperatura de ,ierbere mai mic a-otul iar la ba-' lichidul mai pu#in volatil' oigenul%p.,.&1V3P"*. Xrmele de oigen' care mairm2n 5n a-ot' se 5ndeprtea- de regul printrecerea peste cupru incandescent' c2nd are
loc reac#ia: "u C ; ? "u;
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N' Q proprietati chimice
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N' Q Xtili-ari! Azotulse transport' 5n stare ga-oas' sub presiune' 5n
butelii la 174 atm' sau ca lichid' la temperaturi ,oarte Toase
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N' Q Xtili-ari
! 7osforul este utili-at pentru ob#inerea chibriturilor i 5npirotehnie pentru bombe incendiare' grenade ,umigene'
proiectile trasoare etc. 0ei este un element nedorit 5no#eluri' 5n general 5n aliaTe metalice' totui mici cantit#i suntcon#inute 5n aliaTe alturi de e' "u sau Rn. Xn eemplu 5lconstituie bron-urile cu ,os,or. n o#eluri' un anumit nivel alconcentra#iei Q asigur prelucrabilitate prin achiere dar ire-isten# la u-ur.
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Jrinitrotoluene
JNJ
! JNJ is eplosive ,or two reasons. irst' it contains theelements carbon' oygen and nitrogen' which means thatwhen the material burns it produces highly stablesubstances %";' "; and N* with strong bonds' soreleasing a great deal o, energy. Jhis is a common ,eatureo, most eplosives+ they invariably consist o, many nitrogen
or oygen containing groups %usually in the ,orm o, ' 3 ormore nitrogroups*' attached to a small' constricted organicbac6bone.
(moniac S acid a-otic proprietati chimice
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(moniac S acid a-otic proprietati chimice
Cl2
NH4Cl + N2
O2
N2+ H2O
O2
#tJ $%%% Co
NO + H2O
Na
NaNH2+ H2
N2+ 3H2
NH3
CuO
Cu + N2+ H2O
HANH4A
+ !
Cu2+
[Cu(NH3)42+
HNO3
C
CO2+ NO2
'2
H'O3+ NO
M M(NO3)2+ H2
M''
M(NO3)2+ NO
C1H1(H2SO4)
C1H,!NO2
9licerinaNitro!licerina
Celuloza
Nitro!celuloza
(H2SO4)
H+
Sn
Sn(OH)4+ NO
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As% Sb% Bi 6 proprietati chimice
M (A" S Bi)
MX3 MX,O2
A"4O1 S4O1 Bi2O3H3A"O3 S4O1 Bi3+
H3A"O, S2O,
MH2 H3A" H3S
S
M2S3
H+
Na
Na3M
H3A"O3 S3+
Bi3+
OH!
A"O3!+ H2
HNO3
( Rb Bi J i it t
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(s' Rb' Bi Joicitate! (s' Rb i toate combinaiile lor* inclusi> oxizii i srurile sunt
toxice. Bi nu este toic dar compuii si' cu unele ecep#ii'sunt tot toici. Eolatilitatea (s i a multor compui ai acestuiaasociat cu toicitatea ridicat a acestora ,ace ca acestelement s ,ie deosebit de periculos pentru mediul ambiant.
! (rsenul i compuii si pot aprea ca i poluan#i ai apei sauai aerului. La ,el ca i =g' (s poate ,i trans,ormat' de ctrebacterii' 5n metil-deri>ai* mai mobili i mai toici con,ormreac#iilor: H3A"O4+ 2H++ 2e!8 H3A"O3+ H2O
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Rul,ul pr. chimice
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Biochimia sul,ului! Rul,ul este un constituent esen#ial' dei minor' al unor
proteine' care se gsesc 5n toate organismele vii i estepre-ent 5n unii aminoaci-i' cum sunt cistina' cisteina imetionina.
! (t2t 5n proteine c2t i 5n en-ime' sul,ul se gsete sub ,orm
de pun#i RR. Eitamina B1' coen-ima ( i multe altesubstan#e de origin vegetal con#in sul, %de eemplumutarul sau usturoiul' care au chiar gust caracteristic*.Xnele bacterii i alge oidea- =R la R. (cesta este unproces eoterm i repre-int sursa lor de energie vital.
! ermenta#iile sul,uroase' datorate unor microorganismeanaerobe' care 5n procesele de oidare reduc sul,a#ii%R;* la hidrogen sul,urat %=R*' Toac un rol important 5n,ormarea -cmintelor de petrol.
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R' Re' Je Xtili-ri! Sulfulare utili-ri importante mai ales sub ,orm de
combina#ii. Re utili-ea- pe scar larg pentru produc#ia deacid sul,uric %O49 din cantitatea de sul, produs pe planmondial*. (cidul sul,uric se utili-ea- 5n special pentru,abricarea 5ngrmintelor chimice %>49 din produc#ia
mondial* i pentru ob#inerea di,eritelor substan#e chimice.! Rul,i#ii' bisul,i#ii i R; se ,olosesc 5n cantit#i mari cadecoloran#i. Rul,ul elementar se ,olosete la ob#inerea "R iapoi' din acesta' a ""l i a ,ibrelor de visco-. 0easemenea' un domeniu important de utili-are a sul,ului estela >ulcanizarea cauciucului. Re mai ,olosete la ,abricarea,ungicidelor' pesticidelor i a pra,ului de puc. (cesta esteun amestec de a-otat de potasiu %salpetru* AN;3 %
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R' Re' Je Xtili-ri! Seleniulse utili-ea- 5n cea mai mare cantitate pentru
decolorarea sticlei' iar amestecul de "u' R i Re' pentru
colorarea sticlei 5n ro- sau rou. Releniul mai poate ,i utili-at5n construc#ia unor ,otocopiatoare %de tip $ero*' ca,otoreceptor pentru captarea imaginii %un ,ilm sub#ire de Repe suport de (l* sau la construc#ia de celule ,otoelectrice.Releniurile se utili-ea- 5n ,otogra,ie %NaRe* sau caadaosuri 5n o#eluri i aliaTe %aliaTul eRe 5n o#el mretere-isten#a la coro-iune*.
! Releniul este un component esen#ial al organismului uman'5n cantit#i ,oarte mici %urme*' intr2nd 5n compo-i#ia unor
en-ime importante. n cantit#i mari 5ns' seleniul este toic.! elurulse utili-ea- mai ales ca element de aliere 5n o#elurii aliaTe ne,eroase %de "u' (g' Qb*' 5n compo-i#ia unor sticlespeciale %pentru ob#inerea unor gla-uri albastre*' 5n,otogra,ie' la vulcani-area cauciucului etc.
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=alogeni proprietati ,i-ice#ro&rietate F Cl Br ' At
#t KC !22% !$%$ !. $$4
#5 KC !$ !3, ,- $3
Soluilitate!a&= 2%KC ! %%- %2$ %%%2
7lectroneatiitate (#aulin) 4 3 2 2, 22
/%! &otenial electrocimic * 2. $31 $%. %,4 %3
7nerie >e >i"ociere ?@mol!$ $,. 244 $-3 $,$ $$1
6aza atomic= nm 14 -- $$$ 2$ !
6aza ionic= nm $33 $$ $-1 !
Jo#i halogenii au un miros neplcut' caracteristic isunt toici. 0e asemenea to#i se di-olv 5n solven#i
organici.
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=alogeni proprietati chimice
2
X2L
XLX (XLX3XLX, XLX.)
C(Si)CX4(SiX4)
S(Se:e)
SX4(7X1)
#
(A" S)
#X3
MMXn
(1)
(2)
(1) ! #ro>u"ul >e&in>e >e ra&ortul >e
ame"tecare >ar nu "e cuno"c toti
com&u"ii
(2) ! #entru x 2 exce&tie Be com&u"ii
otinuti "unt ionici 6e"tul &rezinta
un caracter coalent
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=alogeni proprietati chimice
X2
HX + HXO
H2O
N2+ HXNH3
HXL
X2 + HXL
H2S (Se :e)
H2SO4 + HXOH!
(H++ X!) + XO!
S2O3
2-
S4O12-
SO2SO2X2
(H2SO4)
CO
COX2
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=alogeni Xtili-ri! 7luorulse utili-ea- pentru ob#inerea industrial a freonilor
%cloro,luorocarburi prescurtat ""* substan#e importantepentru generarea aerosolilor dar i 5n calitate de agen#i,rigori,ici sau agen#i spuman#i %de eemplu pentru ob#inereade polimeri poroi*. Xn anumit sortiment de "" ia gsitaplica#ii 5n calitate de s2nge arti,icial %incolor*. 0e asemenea
se mai utili-ea- 5n sinte-a industrial politetra,luoretilen%prescurtat QJY' un polimer cunoscut i sub denumireacomercial de Je,lon*' care 5n ,unc#ie de numrul de unit#idin lan# poate ,i un lubre,iant %ulei* sau un material plasticre-istent mecanic i termic' utili-at pentru garnituri de
etanare %chiar la presiuni ridicate* sau ca agent ce5mpiedic lipirea %un eemplu vasele acoperite cu QJY*. Jotcu ,luor elementar se sinteti-ea- X> un intermediar 5nvederea separrii i-otopului 37X necesar preparriicombustibilului nuclear.
=alogeni Xtili-ri
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=alogeni Xtili-ri! +lorul se ,olosete pentru sinte-e organice: ob#inerea
triclor,enolului' un desin,ectant sau a clorurii de vinil' din care
se prepar policlorura de vinil %QE"* unul din cei maiutili-a#i polimeri. Rervete de asemenea la ob#inereahipocloritului de sodiu' desin,ectant i agent de albire casnic'a clorurii de >ar' "a;"l' cu utili-ri similare. "lorul a ,ostprimul ga- toic de lupt ,olosit. 0eriva#i ai clorului servesc
aceluiai scop i 5n -ilele noastre' de eemplu iperita "l%"=*R%"=*"l. Yste utili-at tot mai pu#in pentru tratareaapelor potabile 5n vederea desin,ec#iei. Jot din clor sesinteti-ea- unii solven#i industriali importan#i: cloro,ormul'"="l3' teraclorura de carbon' ""l. 0e asemenea se mai
remarc percloretilena sau i 111tricloretanul solven#iutili-a#i industrial 5n degresri sau pentru cur#toriile chimice."loro,ormul' "="l3' a ,ost i primul aneste-ic general ,olosit5n chirurgie. (st-i al#i deriva#i ai halogenilor %e "3"=Br"l*iau luat locul 5n calitate de aneste-ice. n plus' clorura de etil'
"=7"l' este un aneste-ic local.
! Bromul: numeroase sinte-e organice' de eemplu ob#inerea
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1' dibrometanului' un aditiv 5n ben-inele auto ce evitarderea brusc a ben-inei' mrind ci,ra octanic' sinte-a bromclormetanului' "=Br"l lichid ,olosit la stingerea incendiilor
,ormea- 5n pre-en#a cldurii o perdea de ga- greu %densitatemare*' care acoper ,lacra ,r s 5ntre#in arderea. Iodul'sub ,orm de solu#ie alcoolic' 5mpreun cu iodura de potasiu'servete ca desin,ectant i ,ungicid 5n tratamentul le-iunilor
super,iciale sau al anumitor boli ale pielii. 0e asemeneapre-en#a iodului 5n becurile cu incandescen# cunoscute subdenumirea de becuri cu halogen provoac o mrire alumino-it#ii acestora S prelungire a duratei de ,unc#ionare."au-a este descompunerea halogenurii de wol,ram ga-oasepe ,ilamentul incandescent de wol,ram eact acolo unde acestaeste mai sub#ire' deoarece acolo' datorit e,ectului termic alcurentului electric' temperatura ,ilamentului este mai ridicat.Hodo,ormul' "=H3' pe de alt parte' este un desin,ectant mult
utili-at pentru a crui sinte- se ,olosete de asemenea iod.
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=e' Ne' (r' Ar' $e' [n! Inerte8
n 1O> engle-ii Bartlett i Lohman au sinteti-athexacloroplatinatul de xenon prin reac#ia:
$e %g* C Qt>%g*$eKQt>%s* 0escoperirea a ,ost sugerat de o reac#ie de oidare a
oigenului %dintro serie de 5ncercri de a ob#ine oidan#itot mai energici* i anume:
;%g* C Qt>%g*;KQt>%s*(utorul descoperirii a observat c energia de ioni-are a
oigenului molecular %;* este ,oarte apropiat de cea a$e. ncercarea eperimental a ,ost o reuit enonulcomport2nduse analog oigenului molecular.
14O"enter o, hottest stars
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147
14O
emperature%
&
143
141
141
143
147
1433 nm*. =eliul a mai ,ost utili-at',iind uor i nein,lamabil' pentru a con,eri portan# navelor aeriene.
G bil tili i
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Ga-e nobile utili-ari! 4eonul se ,olosete 5n cantit#i mici pentru reclamele luminoase %lmpi
cu neon* unde pre-int' 5n condi#iile ga-elor rare,iate' o culoare rouportocalie. Qentru ob#inerea altor culori se reali-ea- diverse amestecuricu celelalte ga-e inerte.
! &riptonul d' 5n tuburile 5n care au loc descrcri electrice' o luminalbintens gasindui aplica#ii 5n luminile de averti-are de peaeroporturi. iind un element ce apare i prin reac#ii de ,isiune nuclear%bombe nucleare* pre-en#a sa constituie i un indiciu al activit#iinucleare la scara planetar.
! ;enonul se utili-ea- 5n lmpi de genul lmpilor cu halogen pentruautovehicule sau 5n lmpi,ulger %,lashuri sau blit-uri* ,olosite 5n,otogra,ie' d2nd o lumin alb' ,oarte intens' cu toate dimensiunilereduse' permi#2nd ,otogra,ia la lumin arti,icial.