Lien ket hoa hoc[1]

8/9/2019 Lien ket hoa hoc[1]

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Ch-ng I: L thuyt lin kt ha hc

I HC QUC GIA H NI

TRNG I HC KHOA HC T NHIN

chuyn BI DNG GIO VIN CHUYN THPT

lin kt ho hc

H, thng 8 nm 2009


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I. 1. Khi nim phn t v lin kt ha hcPhn t l phn t nh nht ca cht, mang tnh cht c tr-ng cho cht, c

th phn chia thnh cc ht nh hn trong cc phn ng ho hc v c th tn ti clp.

S kt hp gia cc nguyn t t ti trng thi bn vng hn -c gi l linkt ha hc.

I.2. Cc khuynh h-ng hnh thnh lin kt ha hc:I.2.1. Cc khuynh h-ng hnh thnh lin kt - Qui tc bt t (Octet)

Ni dung ca qui tc bt t: Khi tham gia vo lin kt ha hc cc nguyn t ckhuynh h-ng dng chung electron hoc trao i t n cu trc bn ca khhim bn cnh vi 8 hoc 2 electron lp ngoi cng.V d:

. + . Cl:.. ..

..:..H H-Cl:

Na . . Cl Na+ Cl-

(2/8) (2/8/8)

+ NaCl:..

..

(2/8/1) (2/8/7)

I.2.2. Mt s i l-ng c tr-ng cho lin kt ha hcI.2.4.1. di lin kt (d): L khong cch gia hai ht nhn cahai nguyn t lin kt trc tip vi nhau.

V d: Trong phn t n-c, dO-H = 0,940

A . di lin kt gia hai nguyn t A-B c th tnh gn

ng bng tng bn knh ca hai nguyn t A v B H H

0,94 A104028'0

Gia 2 nguyn t cho tr-c, di lin kt gim khi bc lin kt tng

VD:Lin kt C C C = C C | C

E [kcal/mol] 83 143 194D (A0) 1,54 1,34 1,2

I.2.4.2. Gc lin kt: L gc to bi hai na -ng thng xut pht t mt ht nhnnguyn t v i qua ht nhn ca hai nguyn t lin kt trc tip vi nguyn t . Vd: Trong phn t n-c HOH = 104028

Gc lin kt ph thuc vo:+Trng thi lai haca nguyn t trung tm+ m in ca nguyn t trung tm A v phi t X: nguyn t trung tm A c

m in ln s ko my ca i electron lin kt v pha n nhiu hn, hai mmy ca hai lin kt m ln li gn nhau gy ra lc t-ng tc y lm cho ln gc

lin kt tng ln. Nu phi t X c m in ln s gy tc dng ng-c li.I.2.4.3. Nng l-ng lin kt

Nng l-ng lin kt A-B l nng l-ng cn cung cp ph v hon ton lin kt A-B (th-ng -c qui v 1 mol lin kt - kJ/mol hoc kcal/mol).

EH-H = 103 kcal/mol : H2p 2H ( H = 103 kcal/molNng l-ng lin kt (nng l-ng phn li lin kt), v tr tuyt i,chnh bng nng

l-ng hnh thnh lin kt nh-ng ng-c du. Tng nng l-ng cc lin kt trong phn tbng nng l-ng phn li ca phn t .


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- Nng l-ng lin kt gia 2 nguyn t tng cng bc lin kt ( n < i < ba)II. lin kt ionnh ngha lin kt ion: lin kt ion l lin kt ho hc -c to thnh do lc ht tnhin giacc ion mang in ng-c du.

y Bn cht ca lc lin kt ion: l lc ht tnh in. ln ca lc lin kt ion (F) ph thuc vo tr s in tch cacation (q1) v

anion (q2) v bn knh ion cachng ln l-t l r1 v r2.F~ 1 2

2

.q q

r( r= r1+ r2 )

Khi lc lin kt ion cng ln th lin kt ion cng bn, nng l-ng mng l-i ion cngln v lin kt ion kh b phn li, mng l-i ion cng kh b ph v,cc hp cht ion cngkh nng chy, kh b ho tan trong dung mi phn cc hn.

II.3. Cc yu t nh h-ng n s to thnh lin kt ion.

- Nng l-ng ion ho. - i lc vi electron - Nng l-ng mng l-i.

II.3.1. Nng l-ng ion ho.

a) Khi nim: Nng l-ng ion ho l nng l-ng cn thit tch mt electron ra khinguyn t trng thi c bn (trng thi khng kch thch) to racation trng thi kh.

M + I1 p M+ + 1e

M+ + I2 p M2+ + 1e

M2+ + I3 p M3+ + 1e

......M(n - 1)++ In p M

n+ + 1eCc gi tr I1, I2, I3,, In l nng l-ng ion ho th nht, th 2, th 3, v th n.

b) Qui lut: + I1 < I2 < I3


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y Cccp electron dng chung c th do s gp chung ca hai nguyn t tham gialin kt (cng ha tr thng th-ng) hocch do mt nguyn t b ra (cng ha trphi tr).

y S electron gp chung ca mt nguyn t th-ng bng 8 - n (n: s th t canhm nguyn t). Khi ht kh nng gp chung, lin kt vi cc nguyn t cn li -chnh thnh bng cp electron do mt nguyn t b ra (th-ng l nguyn t ca nguyn

t c m in nh hn).V d: Cng thc phn t Cng thc electron Cng thccu to

H2O H :O: H H - O - HSO2 :O:: S: O: O= SpO

III.2. L thuyt c hc l-ng tIII.2.1. Thuyt VB (Valent Bond - Lin kt ha tr)III.2.1.1. Cc lun im c s ca thuyt VB

y Mt cch gn ng,coi cu to e ca nguyn t vn -c bo ton khi hnhthnh phn t t nguyn t, ngha l trong phn t vn c s chuyn ng ca etrong AO. Tuy nhin khi 2 AO ha tr ca hai nguyn t xen ph nhau to lin kt ha

hc th vng xen ph l chung cho hai nguyn t.y Mi mt lin kt ha hc gia hai nguyn t -c m bo bi 2 e c spin isong m trong tr-ng hp chung, tr-c khi tham gia lin kt, mi e l e c thn trong1 AO ha tr ca mt nguyn t. Mi lin kt ha hc -c to thnh l mt lin kt 2tm (2 nguyn t). Lin kt khng th hnh thnh t 1 e (thiu e) hoc t 3e tr ln(tnh bo haca lin kt cng ha tr).

y S xen ph gia 2 AO c 2e ca 2 nguyn t cng mnh th lin kt -c to racng bn (nguyn l xen phcc i). Lin kt ha hc -c phn b theo ph-ng ckh nng ln v s xen ph 2 AO (thuyt ha tr nh h-ng).III.2.1.2. Thuyt VB v s hnh thnh lin kt cng ha tr

Lin kt gia hai nguyn t cng bn nu mc xen phcacc obitan cng

ln, nh- vy s xen phcacc obitan tun theo nguyn l xen phcc i: lin kt-c phn b theo ph-ng no m mc xen ph cc obitan lin kt c gi tr cc i

7 6 5

HH

HCl H :Cl H ClClH

Cl2 Cl : Cl Cl Cl ClCl

III.2.1.3. Thuyt VB v vn ha tr ca nguyn t trong hp cht cng ha try Cng ha tr ca mt nguyn t (ha tr nguyn t) bng s lin kt m nguyn

t c th to -c vi cc nguyn t khc.V d: Trong CO2 (O= C =O) nguyn t C v O ln l-t c ha tr bng 4 v 2

....

..

.. ....


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y Theo thuyt VB, to -c mt lin kt cng ha tr, nguyn t s dng mte c thn cachng. Nh- vy,c th ni rng cng ha tr ca mt nguyn t bngs e c thn ca nguyn t dng tham gia lin kt.

y Cng theo thuyt VB, khi tham gia lin kt cc nguyn t c th b kch thch.S kch thch ny c nh h-ng n cu hnh e ca nguyn t,cc e cp i c thtch ra v chim c cc AO cn trng trong cng mt lp. Nh- vy s e c thn ca

nguyn t c th thay i v cng ha tr ca nguyn t c th c gi tr khc nhautrong nhng hp cht khc nhau (Bng 2).VD1: Cng ha tr ca S trong H2S l 2 ; SO2 l 4 ; H2SO4 lVD2: Cng ha tr ca Clo trong HClO l 1; HClO2 l 3 ; HClO3 l 5; HClO4 l

Bng 2: S e c thn c th c ca cc nguyn t thuc phn nhm chnh

Nhm Cu hnh electron ha tr S e- c thnIIA ns2

X*

2

IIIA ns2np1

X*

1, 3

IVA ns2np2

X*

2, 4

VAT chu k 3

ns2 np3

X*

3, 5

VIA

T chu k 3

ns2np4

X*

X**

2,4, 6

VIIA

T chu k 3

ns2 np5

*

**

***

1, 3, 5, 7

III.2.1.5. Bc lin ktBc lin kt l s lin kt cng ha tr (s cp electron chung) gia hai nguyn

t.a) Lin kt bc mt (lin kt n):ch c mt lin kt cng ha tr gia 2 nguyn t .VD: H-H ; H- Cl b) Lin kt bc 2 (lin kt i):c 2 lin kt cng ha tr gia 2 nguyn tVD: O= C =O c) Lin kt bc ba (lin kt ba):c 3 lin kt cng ha tr gia 2 nguyn tVD: N | N ; H- C |C - H ,


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Cc lin kt i v lin kt bacn -c gi chung l lin kt bi.Khi s electron chung cng ln, lc ht tnh in gia electron vi ht nhn ca

hai nguyn t cng mnh, bn lin kt tng cn khong cch gia hai tm nguyn tgim. Do vy khi bc lin kt cng ln th nng l-ng lin kt cng ln v di lin ktcng nh.VD: Lin kt: C - C C = C C | C

E (kcal/mol): 83 143 194dC-C (

0

A ) : 1,54 1,34 1,2

III.2.1.6. Lin kt xichma (W) v lin kt pi (T).a) Lin kt xichma (W) : l loi lin kt cng ha tr -c hnh thnh bng ph-ng phpxen ph ng trccc obitan nguyn t, vng xen ph nm trn trc lin kt.

Lin kt Wccc loi Ws-s,Ws-p,Wp-p,

ss pspp

Lin kt W th-ng bn, do c vng xen ph ln v cc nguyn t c th quay t do

xung quanh trc lin kt m khng ph v lin kt ny.b) Lin ktT : L loi lin kt cng ha tr -c hnh thnh bng ph-ng php xen phsong song trccc obitan nguyn t, vng xen ph nm hai pha so vi trc lin kt.

Lin kt Tccc loi Tp-p,Tp-d,Lin kt T km bn do c vng xen ph nh v cc nguyn t khng th quay t

do xung quanh trc lin kt m khng ph v lin kt ny.z z

y

y

x

x

z z

y

Lin kt n lun l lin kt W, lin kt i gm 1 lin kt W v 1 lin kt T, lin

kt ba gm 1 lin kt W v 2 lin kt T.

III.2.1.7. Lin kt cng ho tr cho-nhn (lin kt phi tr).

a) nh ngha: Lin kt cng ho tr cho - nhn l lin kt cng ho tr trong cpelectron dng chung ch do mt nguyn t cung cp gi l nguyn t cho, nguyn tcn li l nguyn t nhn.VD:

N

H

H

H

+ H+ N

H

H

H

H

+

hay N

H

H H

+

Tp-p Tp-d


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N

O

O

N

O

O

ay

b) iu kin to ra lin kt cho nhn:- Nguyn t cho phi c lp v e bo ho v cn t nht mt cp e t do (ch-atham gia lin kt) c bn knh nh, m in t-ng i ln.- Nguyn t nhn phi c obitan trng.

III.2.1.8. S lai ha cc obitan nguyn t.y Thuyt lai hacho rng mt s AO c mc nng l-ng gn bng nhau khi tham

gia lin kt c xu h-ng t hp vi nhau to racc AO lai hac nng l-ng thp hn,lin kt hnh thnh bi s xen phcc AO lai ha s bn vng hn.

y S obitan lai ha to thnh bng s obitan nguyn t tham gia lai ha v ccobitan lai ha to rac nng l-ng t-ng -ng. (bng 2)

Bng 3: Mt s c im phn t

Khiu

S lai ha Phn b khng gian cacc obitan lai ha

spp

sps

1800 -ngthng

sp2p

sp2s

1200 Tamgic

sp3p

sp3s

109028 Tdin

sp3d pd

sp3d

s

L-ngthp ytam gic

sp3d2 pd sp3d2

s

Btdin


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y Ng-i tacng d on kiu lai haca nguyn t trn l thuyt: s obitan lai hobng tng s lin kt W m nguyn t to ra v s cp electron t do ca nguyn t (H).Gi tr ca n tnh -c bng 2, 3,4,5, t-ng ng vi cc trng thi lai ha sp, sp2, sp3,sp3d, sp3d2.

V d: H-O-H , HO = 2+2 = 4p O lai ha sp3

O=S pO , HS = 2+1 = 3 p S lai ha sp2 ; O=C=O , HC = 2+0 = 2 p C lai ha sp

y D-i y l mt s v d v s hnh thnh phn t trn c s kt hp thuyt VBv thuyt lai hacc obitan nguyn t :

CH4 (C lai ha sp3)

H

H

H

H

CH2 = CH2 (C lai ha sp2)

H

........................

........................H

H

H

CH | CH (C lai ha sp)........................

........................

........................

........................

III.1.2.11. Mt s tnh cht ca phn t1- M hnh s y gia cc i electron v ha tr

- Qui -c: Trong phn t ccng thc AXnEm th A l nguyn t trung tm, X lphi t, n l ch s cho bit s phi t, E l i e ring, m l ch s cho bit s i ering

- Mi my electron chim mt khong khng gian nht nh. Hnh dng caphn t ph thuc vo khong khng gian chim bi cc my electron v ha tr ca Ahay hnh dng phn t ph thuc vo s phn b cc i electron hay cc my electron v ha tr ca nguyn t trung tm A

- Ni dung m hnh s y cc i electron v ha tr: Cc i (hay cp electrontrong v ha tr -c phn b cch nhau ti mc xa nht c th -c (hay cc ielectron trong v ha tr y nhau ra xa ti mcc th -c) lc y giachng mc thp nht

- i electron ring ch chu lc ht ca ht nhn nguyn t trung tmA. Cn ie lin kt chu tc dng ht cac hai ht nhn nguyn t tham gia lin kt l A v X.Do i electron ring ca my electron chim khong khng gian rng hn khongkhng gian chim bi my electron ca i electron lin kt2- Hnh dng mt s phn t1. Tr-ng hp AXn (n = 2p6)

Nguyn t trung tm A c t 2 n cp electron lin kt to vi phi t X, Akhng c i electron ring

+Khi n = 2 : hai i e lin kt -c phn b trn -ng thng p phn t c dng-ng thng, gc lin kt 1800

VD: BeH2 : H - Be - H

+Khi n = 3: ba i electron ny -c phn b trn mt phng h-ng v 3 nhca tam gic u p phn t c hnh tam gic u, gc lin kt 1200

VD: BF3, AlCl3,.... F|

Be

F F


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+Khi n= 4:4 i electron h-ng v 4 nh ca t din u, A tm p phnt c hnh t din u, gc lin kt bng 109,50

VD: CH4; NH4+

+Khi n = 5:5 i electron -c phn b trn 5 nh ca l-ng thp tam gicp Phn t hnh l-ng thp tam gic

C 3 i electron nm trn mt phng tam gic u, tm ca tam gic l ht

nhn ca A. Ba i e ny to 3 lin kt ngang, gc lin kt 1200

Cn li 2 i e nm trn -ng thng vung gc vi tam gic ti tm A to 2 lin kt

trc. di lin kt ngang < lin kt trc v i e trn lin kt trcchu t-ng tc y

ca 3 i e ngang, gc t-ng tc900p lc y ln p di lin kt ln,cn i e trnlin kt ngang chu t-ng tc y ca 2 i e trc, 2 i e ngang cn li nh-ng t-ng tcy ca 2 i e ngang l yu v gc t-ng tc l ln 1200p lc y yu hn p dilin kt nh hn. VD: PCl5

+ Khi n = 6:c i e -c phn b trn bt din u. Cc gc lin kt nh-nhau (900)nn di lin kt nh- nhau v lc y t-ng h cacc i e l nh- nhau pphn t hnh bt din u

VD: SF 2) Tr-ng hp AXnEm:ngoi phi t nguyn t trung tm A c i e ring

Cn l-u n s khng t-ng -ng gia i e lin kt vi i e ring ny+AX2E: i e ring c my e chim khong khng gian rng hn i electron lin ktnn 3 nguyn t X A X khng cn nm trn cng 1 -ng thng nh- trong AX2, phnt c gc: gc XAX < 1200

..A

X X+ AX3E: Phn t hnh thp tam gic, gc lin kt < gcca t din u (109,5

0)

VD: NH3; ccamin+ AX2E2: C 2 i e ring nn khc vi AX4 v AX3E m phn t c gc, do t-ng tc yca 2 i e ring p gc lin kt < 109,50. VD: H2O+ AXE3: Phn t thng. VD: cc HX+ AX4E, AX3E2, AX2E3: xt t tr-ng hp AX5My e ngang to vi my e trc gc900, giacc my e ngang to vi nhau gc 1200 nnnu c i e ring th i e ring ny s phn b trn mt phng tam gic v khi lc y t-ng h gia i e ring vi cc i e lin kt l nh nhtVy tac th ccc dng hnh cacc tr-ng hp trn nh- sau

- AX4E: hnh ci bp bnh, do s y ca i e ring mnh nn gcca lin kttrc v lin kt ngang < 900, gc lin kt ngang vi lin kt ngang < 1200

VD: SF4,- AX3E2: 2 i electron ring nm trn mt phng tam gicp phn t hnh ch T,

gc lin kt ca lin kt ngang v lin kt trc < 900VD: ClF3, HClO2- AX2E3: 3 i e ring u phn b trn 1 mt phng, 2 i e lin kt nm trn

trc vung gc vi mt phng p phn t c dng -ng thngVD: ClF2, HOCl

+ AX5E, AX4E2, .....: xut pht t hnh dng ca phn t AX


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- AX5E: 4 i e lin kt phn b trong mt phng hnh vung, 1 i e trn trc,i e khng lin kt nm trn trccn li. Do i e khng lin kt chim khongkhng gian ln nn gc lin kt gia lin kt trc vi lin kt ngang < 900, dilin kt trc < di lin kt ngang ( lin kt trc b y yu hn so vi lin ktngang)

VD: BrF5

- AX4E2: lc y l nh nht th 2 i e ring phi phn b sao cho gc yl ln nht p hai i e ring nm trn trc vung gc vi mt phng cha4 i elin kt cn li p phn t vung phng

VD: XeF4Bng d-i y l mt s m hnh cu trc hnh hcca phn t

-ngthng

Ch V Tamgic

phng

Thp tamgic

Tdin

L-ng thpy tam gic

Vungphng

Thpvung

Btdin

* Mi loi lai ha c kh nng to ra mt hay mt s cu trc no :y Lai ha sp: To cu trc -ng thng (nh- trong cc phn t BeH2, ZnCl2, CO2,

C2H2,).H C C H

y Lai ha sp2: To cu trcch V( nh- trong cc phn t SO2, O3,), tam gicphng (nh- trong cc phn t v ion: BF3, SO3, HNO3, C2H4, NO3

-, CO3

2-).

S

OO

H O N

O

O- y Lai ha sp3: To cu trcch V (nh- trong cc phn t H2O, H2S,), thp tam

gic (nh- NH3, H3O

,) v t din (nh- trong cc phn t v ion: CH4, CCl4, NH4+, PO4

3-

, SO42-, ClO4

-,).

O

H H

N

HHH

H

C

HHH

y Lai ha sp3d: To cu trc thng (nh- XeF2),ch T (nh- ClF3), l-ng thp tam gic

(nh- trong phn t PCl5,).

F Xe F F Cl F

F

P Cl

Cl

Cl

Cl

Cl y Lai ha sp3d2: To cu trc vung phng (nh- trong phn t XeF4, ), thp

vung (nh- trong phn t BrF5 ) v cu trc bt din (nh-: SF , AlF 3-, SiF

2- )


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F

Xe

F

F

F

F

Br

F

F

F

F

F

S

F

F

F

F

F b) S phn cc ca phn t

y L-ng cc in: L-ng cc in l mt h gm hai in tch+q v -q cch nhau mt khong cch l. L-ng cc in c tr-ng bngi l-ng momen l-ng ccQ vi nh nghamomen l-ng ccQ bngtch ca in tch q v cch tay n l. Q = l.q +q

-q

l

l-ng cc in

Trong h SI momen l-ng ccQ -c tnh bng Cm (coulomb.met). Vi phn tdo momen l-ng ccc gi tr nh nn ng-i ta th-ng tnh theo D (Debye) vi qui -c :

1D =1

3.10-29 Cm

y L-ng cc lin kt: mi lin kt ion hoc lin kt cng ha tr phn cc l mtl-ng cc in v c mt momen l-ng cc xc nh -c gi l momen l-ng cc linkt. Lin kt phn cccng mnh th momen l-ng cccng ln.

V d: HF HCl HBr HILin kt H F H Cl H Br H IQ (D) 1,83 1,08 0,82 0,44

y L-ng cc phn t: Trong vic kho st l-ng cc phn t, ng-i ta tha nhnthuc tnh cng tnh ca momen l-ng cc lin kt v coi momen l-ng ccca phn tl tng vect cc momen l-ng cc lin kt.

V d:Vi phn t CO2 : O = C = O Q = 0

Vi phn t H2O : Q{ 0 (Q = 1,84D)y Vic kho st momen l-ng cc phn t l mt thng s cn thit cho vic

nghin cu tnh cht ca lin kt (khi Qcng ln, tnh ion ca lin kt cng mnh),cutrc hnh hcca phn t cng nh- cc tnh cht vt l, ha hcca mt cht.c) T tnh ca phn t

y Cht thun t: Cht thun t l nhng cht b ht bi nam chm. V mt cuto, phn t cacccht ny c e ch-a ghp i ( e c thn).V d: NO2 l mt cht thun t do trong cu to cn mt e c thn trn nguyn t N :

O = NpOy Cht nghch t: Cht nghch t l nhng cht b y bi nam chm. V mt

cu to, phn t cacht ny khng c e c thn.

IV. Lin kt kim loiIV.1. nh ngha: Lin kt kim loi l lin kt ho hc hnh thnh do cc electron t dogn kt cc ion d-ng kim loi trong mang tinh th kim loi hay trong kim loi lng.

y Bn cht ca lc lin kt kim loi l lc ht tnh in giacc electron t do v ccion (+) kim loi.


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IV.2. Mt s kiu mng tinh th kim loi.

IV.2.1. Mng lp ph-ng n gin:

- nh khi lp ph-ng l cc nguyn t kim loi hay iond-ng kim loi; S phi tr = .

IV.2.2. Mng lp ph-ng tm khi:- nh v tm khi hp lp ph-ng l nguyn t hay ion

d-ng kim loi; S phi tr = 8.

IV.2.3. Mng lp ph-ng tm din

- nh v tm cc mt ca khi hp lp ph-ng l ccnguyn t hoc ion d-ng kim loi; S phi tr = 12.

IV.2. 4. Mng su ph-ng c kht (mng lc ph-ng):

- Khi lng tr lc gic gm 3 mng c s. Mi mng cs l mt khi hp hnh thoi. Cc nh v tm khi hp hnh thoil nguyn t hay ion kim loi;

- S phi tr = 12.

IV.3. nh h-ng ca lin kt kim loi n tnh cht vt l ca kim loi

Do cu trc c bit ca mng tinh th kim loi m cc kim loi rn c nhngtnh cht vt l chung: tnh dn in, tnh dn nhit, tnh do, nh kim. Cc tnh cht

vt l chung u do electron t do trong kim loi gy ra.Ngoi ra c im ca lin kt kim loi: Mt nguyn t (hay c kht),mt electron t do, in tch cacation kim loi cng nh h-ng n cc tnh chtvt l khcca kim loi nh-: cng, nhit nng chy, nhit si, t khi.IV.4. c kht ca mng tinh th, khi l-ng ring ca kim loi.IV.4.1. c kht ca mng tinh tha) Mng tinh th lp ph-ng tm khi

2

3a

a

a

= 4r

Squcutrongmtcs:1+8.1/8 = 2

Tngthtchqucu 34

2. .3

rT 34 3

2. .( )3 4

aT

== = 8%


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Th tch ca mt c s a3 a3

b) Mng tinh th lp ph-ng tm din

a

a

a 2 = .r S qu cu trong mt c s : . 1/2 + 8. 1/8 = 4

Tng th tch qu cu 34

4. .3

rT 34 2

4. .( )3 4

aT

Th tch ca mt c s a3 a3

c) Mng tinh th lc ph-ng cht khtS qu cu trong mt c s: 4. 1/ +4. 1/12 + 1 = 2

Tng th tch qu cu 34

2. .3

rT 34

2. .( )3 2

aT

Th tch ca mt c s3 2 . 6

. .2 2

aa a 3 2a

a

a

a

a

aa

aa

a c

a

IV.4.2. Khi l-ng ring ca kim loia) Cng thc tnh khi l-ng ring ca kim loi

D =3

3. .

4 .A

M P

r NT(*)

M : Khi l-ng kim loi (g) ; NA: S AvogaroP : c kht (mng lp ph-ng tm khi P = 8%; mng lp ph-ng tm

din, lc ph-ng cht kht P = 4%)r : Bn knh nguyn t (cm)

b) p dng:V d 1: Tnh khi l-ng ring ca tinh th Ni, bit Ni kt tinh theo mng tinh th

lp ph-ng tm mt v bn knh ca Ni l 1,240

A .

= = = 4%

= = =


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14

= 4 r

a =04 4 1, 4

3,507( )r

! ! ; P= 0,74

Khi l-ng ring ca Ni:

8 3 23

3.58,7.0,74

4.3,14.(1,24.10 ) .6, 02.10

=9,04 (g/cm3)

V d 2: Xc nh khi l-ng ring ca Na, Mg, KKim loi Na Mg Al

Nguyn t khi (v.C) 22,99 24,31 2 ,98

Bn knh nguyn t (0

A ) 1,89 1,6 1,43

Mng tinh th Lptk Lpck Lptm c kht 0,68 0,74 0,74

Khi l-ng ring l thuyt (g/cm3) 0,919 1,742 2,708Khi l-ng ring thc nghim (g/cm3) 0,97 1,74 2,7

V. Lin kt hiroV.1. Khi nim- Lin kt hyro l lin kt ho hc -c hnh thnh bng lc ht tnh in yu giamt nguyn t hyro linh ng vi mt nguyn t phi kim c m in ln, mang intch m ca phn t khc hoc trong cng phn t.

H

H

VD

O

HH

O

H

H

O

H

H

V.2. Bn cht ca lc lin kt hyro.

- Bn cht ca lc lin kt hyro l lc ht tnh in.- Lin kt hiro thuc loi lin kt yu,c nng l-ng lin kt vo khong 10-40 kJ/mol,yu hn nhiu so vi lin kt cng ha tr m nng l-ng lin kt vo khong v trmn vi ngn kJ/mol, nh-ng li gy nn nhng nh h-ng quan trng ln tnh cht vt l(nh- nhit si v tnh tan trong n-c) cng nh- tnh cht ha hc (nh- tnh axit) canhiu cht hu c.

HH

HX ... :

1HY

V.3. iu kin hnh thnh lin kt hyr.+Xphi c m in cao, bn knh nguyn t phi t-ng i nh( O, N, F)+Y: ct nht mt cp e ch-a s dng, c r nh (O, N, F)- C 2 loi lin kt H+Lin kt H gia cc phn t ( lin kt H lin phn t)VD:


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15

R

R

C th c loi lin kt lin phn t to thnh vng khp kn (dng ime) rtbn rt kh tch nhau ra ngay c khi bay hi

+ Lin kt H ni phn t: Xut hin trong phn t cc

HH

HX v :

1H

Y vchng phi t-ng i gn nhau khi hnh thnh lin kt H to thnh -c vng5-6 cnh ( th-ng th vng 5cnh bn hn)

VD C 2 2C

O

O

C

O

O

O

;

y Trong phn t c lin kt H ni phn t: ngoi ra cn c lin kt H lin phn t

nh-ng v cng kh khn v n to ra lin kt H ni phn t d dng hn v bnhn lin kt H lin phn tb) nh h-ng ca lin kt H+) nh h-ng n si, nhit nng chy- Lin kt hyro lin phn t lm tng nhit nng chy, nhit si, sccng bmt v kh nng ho tan vo n-ccacht.- Cccht c lin kt hyro ni phn t s gim kh nng to lin kt hyro lin phn t,lm gim nhit nng chy, nhit si, kh nng ho lng so vi hp cht c khil-ng phn t t-ng -ng nh-ng c lin kt hyro lin phn t.

CH

(I)

CH

(II)

VD

(II) c nhit nng chy v nhit si cao hn(I).

+) nh h-ng n tan: Xt nh h-ng ca lin kt H gia phn t v dung mi- Nu c lin kt H gia phn t hp cht v dung mi th tan ln- Nhng cht c kh nng to lin kt H ni phn t d tan trong dung mi khng phncc, kh tan trong dung mi phn cc hn so vi nhng cht c lin kt H lin phn tVD: Do c lin kt hyro nn H2O, NH3, HF c nhit si cao hn cc hp cht c khi

l-ng phn t t-ng -ng(hoc ln hn) nh-ng khng c lin kt hyro nh- H2S, HBr,HI... Lin kt hyro ca C2H5OH vi H2O lm cho r-u etylic tan v hn trong n-c.

...O - H

C2H5

... H- O

C2H5

...

O - H

C2H5

...O - H

H

... O - H

H

......

+) nh h-ng n bn ca ng phnVD: Hin t-ng ng phn tautome:

H+H

- H

+H

- H

+H

-

CH

CH3 C C CH

|| ||

- H ...


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16

+) nh h-ng n tnh axit baz

- Ngoi ra lin kt hyro cn nh h-ng n kh nng cho v nhn proton(H+

), tc nhh-ng n tnh axit-baz cacht.VD: HF to lin kt hyro mnh trong dung dch nn tnh axit ca HF gim mnhso vi cc axit HCl, HBr, HI.

VI. lin kt Vanecvan (Lin kt phn t)VI.1. nh ngha:

Lin kt Vanecvan l lin kt ho hc -c hnh thnh bng lc ht tnh in

rt yu giacc phn t phn cc th-ng trc hay phn cc tm thi.

Lc lin kt Vanecvan hnh thnh gia tp hp cacccht rn, lng, kh.

VI.2. Cc yu t nh h-ng ti lc lin kt Vanecvan.

ln ca lc lin kt Vanecvan ph thuc vo cc yu t sau: (K hiu F l lclin kt vanecvan):

- phn ccca phn t cng tng th F tng.

- Khong cch giacc phn t cng gim th F cng tng.

- Khi l-ng phn t cng tng th F cng tng.

VI.2.1. T-ng tc Vanecvan gm :- T-ng tc l-ng cc: l t-ng tc tnh in giacc phn t phn cc. T-ng

tc l-ng lc tng khi phn ccca phn t tng.- T-ng tc cm ng: Kh nng lm phn cc ho ln nhau cacc phn t. Cc

hp cht ccha lin kt T linh ng,chacccp electron ho tr t do,cc hp cht

thm l nhng cht d b phn cc ho, nn t-ng tccm ng giachng kh mnh.- T-ng tc khuych tn : T-ng tc ny ph thuc vo kch th-c phn t v lc

ht giacc phn t. Cc phn t c kch th-ccng nh,cng c tnh i xng caov ccu trc t-ng ng nhau th cng d khuych tn vo nhau (d tan vo nhau nu cmt cht lng).VI.2.2. nh h-ng ca lc htVanecvan n tnh cht vt l ca cc cht : - T-ng t nh h-ng ca lin kt hyro nh-ng yu hn : T-ng tc Vanecvan cngmnh th cht c nhit nng chy, nhit si cng cao,cng d ho lng, tanvo nhau ng k.

V d : SO2c nhit nng chy, nhit si cao hn CO2, do :MSO2 = 64 > MCO2 = 44

Phn t SO2 phn cc, phn t CO2 khng phn cc

S

O O O = C = O

Q> 0 Q= 0

2H

H H

H H 2H

CH3 C CH2 C CH3

|| ||


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17

Do vy lc lin kt Vanecvan giacc phn t SO2 ln hn giacc phn tCO2 lm cho nhit si ca SO2cao hn CO2.

Ch-ng II:bi tp V lin kt ha hc

I. Cu to phn t v lin kt ha hc:

Bi 1. Hy cho bit kiu lai ho cacc nguyn t v loi lin kt (W,T) trong cc hp chtsau:Cl CH2 CH = O ; CH2= CH C | N ; CH2= C = OBi 2. Axit 3-aminobenzoicccu to nh- hnh v bn. Hy xc nh ho tr v s

oxiho ca tt c cc nguyn t v trng thi lai ho cacc nguyn t trung tm trongcng thc cho v gii thch.

Bi 3. Cho phn t: ClF3 hy: - Vit cng thccu to; Cho bit kiu lai ho trong phnt; M t hnh dng phn t. Cho: Q ( phn cc) ca phn t l O,55 D ; gc linkt FClF = 870 . Gii thch

Bi 4. phn ly nhit (tnh theo %) 1000 K cacc halogen:F2 Cl2 Br2 I2

% 4,3 0,035 0,23 2,8Hy nu quy lut chung ca s bin thin phn ly nhit, gii thch s bt th-ng v phn ly nhit t F2 n Cl2

Bi 5. Cho cc tr s gc lin kt trong phn t PX3: 100,30; 97,80; 101,50; 1020 v cc

gc lin kt IPI; FPF; ClPCl ; BrPBr. Hy gn tr s cho mi gc lin kt v giithch.

Bi 6. a) Ti sao trong cc phn t H2O,NH3cc gc lin kt HOH (104,290) v HNH

(1070) li nh hn gc t din (1090,28 ) ?

b) Xt 2 phn t H2O v H2S ti sao gc HSH (92015) li nh hn HOH (104029)

c) Xt 2 phn tH

2O

v F2O

ti sao gc

FO

F(103

0

15) li nh hnHOH

(1040

29)Bi 7. Cho cc phn t: Cl2O ; O3 ; SO2 ; NO2 ; CO2 v cc tr s gc lin kt: 1200 ;

1110 ; 1320 ; 116,50 ; 1800. Hy ghi gi tr gc lin kt trn cho ph hp vi cc phn tt-ng ng v gii thch (ngn gn)

Bi 8. Mt trong bacht hu c sau: ortho-diclobenzen ; meta-diclobenzen ;para-iclobenzen c momen l-ng cc bng 1,53 D. Hy ch r l cht no? c giithch, bit rng mnclobenzen c momen l-ng cc l 1,53D).

Bi 9. C5cht hu c vi cc gi tr mmen l-ng cc t-ng ng nh- sau:Cht hu c A B C D E

Q (D) 0,0 1,89 1,97 1,71 2,13Bit A, B, C, D, E thuc trong cccht sau:

cis - CHCl = CHCl ; cis - CH3 CH = CH Cl ; trans - CHCl = CHCl;trans - CH3 CH = CHCl vtrans - CH3 CH = CH COOH .Hy ch r A,B,C,D,E l nhng cht no? gii thch.

Bi 10. Gii thch ti sao : nhit th-ng, l-u hunh c tnh tr v ha hc nh-ngkhi un nng th hot ng ha hc tng ?

Bi 11. Trong phn t HCHO c 2 gc lin kt l 1160 v 1220. Hy cho bit l gcno? Gii thch.

Bi 12: Cho 3 phn t SCl2, F2O, Cl2O vi cc tr s gc o -c bng 1110, 1030, 1050.

Hi l nhng gc no? Gii thch.


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18

Bi 13. Gii thch ti sao CCl4 l hp cht tr, khng b thu phn trong H2O,cn SiCl4li b thu phn rt mnh trong H2O. Vit ph-ng trnh phn ng.Bi 14. M t cu trccc phn t N(CH3)3 v N(SiH3)3. So snh gc lin kt CNC vi

SiNSi. So snh tnh baz gia 2 hp cht trn.Bi 15. Hp cht A c tng s electron trong phn t = 100. A -c to thnh t 2 phikim thucccchu k nh v thuc 2 nhm khc nhau. Xc nh cng thc phn t ca

A, bit rng tng s nguyn t cc nguyn t trong A l 6. M t cu to phn t A(hnh dng, kiu lin kt).Xc nh trng thi lai ho ca nguyn t trung tm p hnh dng phn tBi 16. V sao n-c li nh hn n-c lng?H-ng dn : Xc nh v mng tinh th ca n-c -c hnh thnh nh- th no, loilin kt trong tinh th n-c so vi n-c lng t so snh th tch cacng mt l-ngn-c p khi l-ng ringBi 17. Momen l-ng ccca lin kt C Cl bng 1,6D. Triclo- benzen C6H3Cl3 c

momen l-ng cc = 0. Hy ch r cu to ca ng phn ny? Nu cu to ca ngphn C6H3Cl3c momen l-ng cc ln nht v tnh momen .

Bi 18. Axit Flohydric l mt axit yu nht trong ccaxit HX nh-ng li to -c mui axit

cn ccaxit khc th khng c kh nng ny ?Bi19. Bo v Nhm l hai nguyn t k nhau phn nhm IIIA. ti sao c phn tAl2Cl6 nh-ng khng c phn t B2Cl6 ?

Bi 20. C 3 hidrocacbon: C2H6 ; C2H4 ; C2H2 . Ng-i ta ghi -ccc s liu sau:- V gc ho tr (gc lin kt) : 1200 ; 1800 ; 1090 .- V di lin kt: 1,05 ; 1,07 ; 1,09 ; 1,200 ; 1,340 ; 1,540 .- m in ca nguyn t cacbon : 2,5 ; 2,69 ; 2,75 .Hy in cc gi tr ph hp vi tng hidrocacbon theo bng sau:

Hidrocacbon Kiulai ho

Gc hotr

m in canguyn t cacbon

di lin

kt C-C (0

A )

di lin

kt C-H (0

A )

CH3-CH3

CH2 = CH2

CHCH

H-ng dn : Trng thi lai ho cng nh p m in cng ln p di lin kt cngnh

Bi 21. Vit cu trc Lewis ca NO2 v nu dng hnh hcca n. D on dng hnhhcca ion NO2

- v ion NO2+. So snh hnh dng ca 2 ion vi NO2.

Bi 22. Nng l-ng lin kt ca BF3 = 646 kJ/mol cn ca NF3ch = 280 kJ/mol. Giithch s khc bit v nng l-ng lin kt ny.

Bi 23. im si ca NF3 = 1290

C cn ca NH3 = 330

C. Amoniac tc dng nh- mtbaz Lewis cn NF3 th khng. Momen l-ng ccca NH3= 1,46D ln hn nhiu so vimomen l-ng ccca NF3 = 0,24D mc d m in ca F ln hn nhiu so vi H.Hy gii thch.

Bi 24. Ti sao ccc phn t BF3, BCl3, BBr3 nh-ng khng c phn t BH3?Bi 25. Nhm clorua khi ho tan vo mt s dung mi hoc khi bay hi nhit

khng qu cao th tn ti dng ime (Al2Cl6). nhit cao (7000C) ime b

phn li thnh monome (AlCl3). Vit cng thccu to Lewis ca phn t ime v


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19

monome; Cho bit kiu lai ho ca nguyn t nhm, kiu lin kt trong mi phn t; M t cu trc hnh hccacc phn t .

Bi 26. Phn t HF v phn t H2O c momen l-ng cc, phn t khi gn bng nhau(HF =1,91 D, H2O = 1,84 D, MHF = 20,

2H OM = 18); nh-ng nhit nng chy ca

hiroflorua l 830C thp hn nhiu so vi nhit nng chy ca n-c l 00C,hy gii thch v sao?

Bi 27: Khi nghin cu cu trcca PCl5(r), PBr5(r) trng thi tinh th bng tia X ng-i tathy:a) PCl5 gm cc ion [PCl4]

+; [PCl6] phn b trong tinh th.

b) PBr5 gm cc ion [PBr4]+; Br .

Hy cho bit cu trc khng gian cacc phn t v gii thch ti sao c s khc nhautrn?

Bi 29. Dng cu trcca ion SO32 gii thch kh nng phn ng:

2Na2SO3+ O2p 2Na2SO4. v Na2SO3+ S p Na2S2O3.Bi 30. Khuynh h-ng dime ha AlX3 v MCl3 thay i th no khi chuyn t F n I

v khi chuyn t Al n In.Bi 31. Hy v r rng dng hnh hcca 3 anion ?NiCl4A

2-,?PtCl6A

2-,?PdCl4A

2-v cu trcca phn t Pd(NH3)2Cl2. Ghi ng k hiu lp th v gii thch.

Bi 32. Bng thc nghim ng-i ta xc nh -c gi tr momen l-ng ccca phnt H2S l 1,09D v ca lin kt S H l 2,61.10

30 C.m. Hy xc nh:

a) Gc lin kt HSH .b) ion ca lin kt S H , bit rng di lin kt S H l 1,33 . Cho 1D =3,33. 1030C.m. Gi s Qcacp electron khng chiaca S l khng ng k.

Bi 33. Xc nh momen l-ng cc (D)Cl

Quuur

v2NO

Quuuur

trong cc dn xut th 2 ln ca

nhn benzen sau: 1,2 dinitrobenzen (Qur

= 6,6 D); 1,3 diclobenzen (Qur

= 1,5 D);

para nitrToluen (Qur

= 4,4 D); nitrobenzen (Qur

= 4,2 D).

II.1..4.1. Lin kt ionBi 34. M t s chuyn dch electron t nguyn t liti sang nguyn t flo to thnhhp cht litiflorua theo bacch:a) Theo cu hnh electron.b) Theo s obitan (cc l-ng t)c) Theo k hiu Liuyt.Bi 35:. M t s to thnh ion Na+ v O2- t cc nguyn t theo s obitan v k hiuLiuyt. Xc nh cng thcca hp cht ?Bi 3: M t kiu lin kt trong cc hp cht CaO, CaCl2, Ca(OH)2, NaClO3, Na2SO3.Bi 36a) Nng l-ng to thnh mng l-i ion (gi tt l nng l-ng mng l-i , k hiu (Hml )

l g ?- Nng l-ng phn li mng l-i ion l g ?- Quan h gia hai i l-ng trn ?

b) Nhng yu t no nh h-ng n (Hml ?c) (Hml nh h-ng n nhng tnh cht no cacc tinh th ion ?Bi 37:. 1)D on xem hp cht no sau y c nhit nng chy cao hn, ha tantrong n-c nhiu hn ? V sao ?a) NaCl v bCl b) CsCl v NaCl c) NaI hay LiF d) CsI hay CsBr2) on xem nhit nng chy cacht no sau y cao hn:


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20

a) MgO v BaO b) NaCl v MgCl2

III.1.4.2. Lin kt cng ha trBi 38. Vit cng thc electron (theo s Liuyt) cacc phn t v ion sau:

a) Amoniac NH3 b) Fomanehit H2COc) Ion hipoclorit Ocl- d) Ion nitroni NO2

+- Da vo quy tc no vit nhng cng thc ?

Bi 39. Vit cng thccacc phn t v ion sau theo s Liuyt:a) Cl2, N2 b) H2S, SO2, SO3, H2O, CO, HCNc) NH4

+, NO+ d) NO2

-, NO3

-, CO3

2-, SO3

2-, PO4

3-, SO4

2-, ClO2

-, ClO3

-, ClO4

-

Bi 40.Xt lin kt cacbon-oxi trong fomalehit H2CO v trong cacbon monoxit CO.- Trong phn t no lin kt cacbon-oxi ngn hn ?- Trong phn t no lin kt cacbon-oxi bn hn ? V sao ?Bi 41. So snh lin kt nit - nitr trong hirazin H2NNH2 v trong kh c-i N2O.- Trong phn t no lin kt nit - nit ngn hn ?- Trong phn t no lin kt nit - nit bn hn ? V sao ?HD: Lin kt nit-nit trong hirazin l lin kt n,cn lin kt nit-nit trong khc-i N2O l lin kt ba nn lin kt nit-nit trong phn t hirazin ngn hn v km

bn hn trong lin kt nit-nit N2O.Bi 42. a) So snh lin kt W v lin kt T.b) Ti sao nng l-ng lin kt i C = C (614 kJ/mol) khng lp gp i nng l-ng lin ktn C C (347 kJ/mol) v ti sao nng l-ng lin kt ba C | C li khng ln gp ba ?Bi 43. Da vo cng thc Liuyt v nng l-ng lin kt, hy :a) Tnh nhit ca phn ng t chy metan (CH4) ?b) Tnh nhit ca phn ng clo ha metan to thnh CHCl3 ?Bi 44. Da vo nng l-ng lin kt, hy tnh nhit cacc phn ng sau:a) N2 (k) + 3H2 (k) p 2NH3 (k)b) C2H4 (k) + HBr (k) p C2H5Br (k)Bi 45. Bng cch dng mt lung photon vi b-c sng xc nh,cc nh bc hcc thphn li khi hiro ioua (HI) thnh cc nguyn t. Khi HI b phn li,cc nguyn t Hchuyn ng nhanh hn cn cc nguyn t I t-ng i nng nn chuyn ng chmhn.a) Hi b-c sng di nht l bao nhiu (tnh theo nm) c th phn li -c mt phnt HI ?b) Nu dng mt photon c b-c sng l 254 nm th nng l-ng d- (tnh theo J) l baonhiu so vi nng l-ng cn thit phn li ?c) Nu nguyn t H nhn ton b nng l-ng d- nh- l ng nng th tc ca n lbao nhiu (theo m/s).Cho bit: - Nng l-ng phn li H-I l 295 kJ/mol

- Khi l-ng ca nguyn t H l 1,66.10-27 kg.Bi 46. Cc nh ha hc dng laze pht ra nh sng c nng l-ng xc nh ph v linkt ha hc.a) Hi mt photon phi c nng l-ng ti thiu v tn s l bao nhiu phn li mtphn t Cl2 ?b) Ng-i tacho rng giai on u tin trong qu trnh ph hy tng ozon trn tng bnhl-u do cht clorofloro cacbon (CCl2F2) cng nghip gy ra l s phn li lin kt C-Cl binh sng.


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21

Hi mt photon phi c b-c sng di nht l bao nhiu mi c th gy ra s phn li ?Cho bit: - Nng l-ng phn li Cl Cl l 243kJ/mol.

- Nng l-ng phn li C Cl l 339 kJ/mol.

;

H

N

H

N

H

H

N N

Bi 47.a) C th tn ti cc phn t sau y hay khng ? Gii thch ?

SF6, Cl7F, ClF3b) Gii thch v sao trong dy cc hp cht HF, HCl, HBr, HI nhit si v nhit nng chy ca HF cao hn HCl v tng dn theo th t HCl, HBr, HI.

III.1.5.Dng hnh hc ca phn t :Bi 48. a) Gc lin kt l g ?b) Trong phn t n-c H2O, di lin kt O-H bng 0,96.10

-10m v gc HOH bng104,50. Tnh khong cch gia hai nguyn t H (theo nm) ?Bi 49. a) Cn c vo nguyn tc no xc nh dng hnh hccacc phn t vion n gin.b) Trn thc t th-ng gp nhng dng no ?c) D on dng hnh hcca mt s phn t v ion sau:

- BeCl2, CO2, CS2, HCN, C2H2.- BF3, CH2O, NO3

-, CO3

2-.- CH4, NH4

+, SO4

2-, PO4

3-.

- NH3, PH3, H3O+, PF3.

- H2O, SO2, SCl2, OF2

d) Hy nu mt s b-ccn tin hnh xc nh dng hnh hccacc phn t trn.e) Nhn xt v mi lin h gia s nhm electron xung quanh nguyn t trung tm vdng hnh hccacc phn t nu trong phn c.Bi 50. Trong phn t amoniac NH3, di lin kt l cacc lin kt N - H bng 100pm. Gc lin kt HNH bng 1070. Tnh khong cch gia hai nguyn t hiro (theo pm).Bi 51.a) Dng thuyt obitan lai ha, hy gii thch lin kt ha hc trong H

2S, BeH

2v

SO2.b) Hy cho bit dng hnh hcca NH4

+, PCl5, NH3, SF6 bng hnh v. Xc

nh trng thi lai haca nguyn t trung tm.Bi 52.Hy cho bit dng hnh hc phn t ca SO2 v CO2. T so snh nhit si v ha tan trong n-ccachng.Bi 53. So snh v gii thch:a) Gc ONO trong cc phn t NO2; KNO2; NO2Clb) Gc FBF, HNH, FNF trong cc phn t BF3; NH3; NF3.Bi 54. Clotriflorua (ClF3) l tc nhn flo ha rt mnh -c dng tch urani ra khicc sn phm khcc trong thanh nhin liu ht nhn qua s dng.a) Vit cu trcchm Liuyt ca ClF3.b) Da trn thuyt lin kt ha tr hy v cc dng hnh hc phn t c th cca ClF3.c) M t r dng hnh hc phn t tn ti trong thc t ca ClF3, gii thch v sao ntn ti dng ny.d) Tnh dn in ca ClF3 lng ch hi thp hn n-c. Tnh cht ny -c gii thchl do s t ion haca ClF3 to ion ClF2

+ v ClF4-. V v m t cu trc ph hp t-ng

ng ca hai ion ny.

III.1.5.2. S lai ha cc obitanBi 55. a) Th no l s lai hacc obitan nguyn t ?


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b) C my kiu lai ha ?Bi 56. Trong tr-ng hp no th xy ra s lai ha sp, sp2, sp3 ? Khi mt nguyn t laiha theo kiu sp, sp2, sp3cn bao nhiu obitan p thun tu (tc l khng lai ha)trong nguyn t ? C th to thnh bao nhiu lin kt T?Bi 57. M t s to thnh cc phn t sau theo thuyt lai ha:

BeF2, HCN, BCl3, H2CO, SiCl4, NH3, H2O, SCl2

Bi 58. C nhng kiu lai ha no xy ra trong phn t axit axetic CH3COOH ?Bi 59.a) Dng thuyt obitan lai ha, hy gii thch lin kt ha hc trong H2S, BeH2 vSO2.Bi 60 V cng thc Liyt ca phn t O3, bit gc lin kt khong 119

0C v di cclin kt nh- nhau. Hi nguyn t oxi trung tm thuc loi lai ha g ?Bi 61.a) M t dng hnh hc phn t, trng thi lai haca nguyn t nguyn t trungtm trong cc phn t: IF5, XeF4, Be(CH3)2.b) So snh ln gc lin kt cacc phn t sau y. Gii thch. PI3, PCl5, PBr3, PF3.Bi 62. Ngy nay, ng-i ta c lp -c mt s hp cht cacc nguyn t kh himnh- Kripton v Xenon.a) Dng thuyt lin kt ha tr, d on hnh hc phn t c th cca XeF2 v XeF4.

b) S oxi haca Xe trong mi hp cht trn l bao nhiu ? Ta d on chng phn ngnh- mt cht oxi ha hay cht kh ?Bi 63. Da vo l thuyt lai hacc obitan, hy gii thch s to thnh cc ion v phnt: [Co(NH3)6]

3+, [MnCl4]2-, [Pt(NH3)2Cl2].

III.1.6. S phn cc lin kt. Phn t phn cc v khng phn ccBi 64. B m in ca C trong C2H6, C2H4, C2H2 t-ng ng bng 2,48; 2,75; 3,29.Hy sp xp bacht trn theo th t gim dn phn ccca lin kt C-H; ly v dphn ng ho hc minh ha v dng cc s liu trn gii thch s sp xp .Bi 65. Trong mi cp lin kt nu sau y, hy nu r lin kt no phn cc hn vdng mi tn ch chiu ca s phn cc (t d-ng sang m) mi lin kt.a) C O v C N b) P O v P S c) P H v P N d) B H v B I

HD: Da vo hiu m in cacc nguyn t to thnh lin kt. Hiu m incng ln th phn ccca lin kt cng ln.Trong lin kt A B ; gi s GA >GB th (G = GA - GB ; (Gcng ln th lin kt A B cngphn cc, theo chiu AnBBi 66. Phn t sau y l acrolein, mt cht u iu ch mt s cht plastic.

..

..

a) Trong phn t, nhng lin kt no phn cc ? Nhng lin kt no khng phn cc ?b) Lin kt no phn cc nht trong phn t ?Bi 67. Cho cc phn t sau:

a) CO2 b) H2O c) NH3 d) NF3- Phn t no c lin kt phn cc nht ?- Phn t no phn cc ? Khng phn cc ? V sao ?Bi 68. Phn t no sau y phn cc ? Khng phn cc ? V sao ?a) BF3 b) HBF3 c) CH4 d) CH3Cl e) CH2Cl2 f) CHCl3 g) CCl4

Bi 6. Cht icloroetilen (cng thc phn t l C2H2Cl2) c ba ng phn k hiu lX, Y, Z.- Cht X khng phn cc,cn cht Z phn cc.- Cht X v cht Z kt hp vi hiro cho cng sn phm.


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C2H2Cl2 (X hoc Z) + H2p ClCH2 CH2Cla) Vit cng thccu to ca X, Y, Z.b) Cht Y c momen l-ng cc khng ?Bi 69. init iflo, l phn t v c bn c ni i N = N. Cht ny tn ti d-i hai dng

ng phn l cis v trans.a) D on gc lin kt trong phn t ca hai dng ng phn trn ?

b) D on xem dng no phn cc ? Khng phn cc ?Bi 70. Clo triflorua l mt trong nhng cht hot ng nht ng-i ta bit. N phnng mnh lit vi nhiu cht -ccoi l tr v -c dng ch to bom chy trong chintranh th gii th II. N -c iu ch bng cch un nng Cl2 v F2 trong thng kn.

a) Vit ph-ng trnh phn ng th hin phn ng iu ch ClF3 t Cl2 v F2.b) Nu trn 0,71g Cl2 vi 1,00g F2 th thu -c ti a bao nhiu gam ClF3c) Vit cng thc Liuyt ca phn t ClF3.d) Bit rng phn t ClF3 phn cc, d kin hnh dng ca phn t ?Bi 71. Giacis icloroetilen v trans icloroetilen,cht no c nhit si ln hn?V sao ?

C C

Cl

Cl

dng cis (Q{ 0)

dng trans (Q = 0)

Bi 72. Cccht no sau y c lin kt hiro ?a) C2H6 b) CH3OH c) CH3 CO NH2

Nu cht no c lin kt hiro, v lin kt hiro gia hai phn t.Bi 73. C nhng lc tc dng no giacc phn t trong mi tr-ng hp sau v sp

xp cc t-ng tc theo chiu mnh dn.a) CH4 CH4 (lng) b) H2O CH3OH c) LiCl H2OBi 74. Cccht sau y cht no c nhit si ln hn:a) CH3NH2 v CH3F b) PH3 v NH3 c) LiCl v HClBi 75. Sp xp cccht sau y theo chiu tng nhit si :

H2S, H2O, CH4, H2, KBrBi 76. Cho cc s liu ca NH3 v NF3 nh- sau:

NH3 NF3

Momen l-ng cc 1,46D 0,24D

Nhit si -330C -1290C

Gii thch s khc nhau v momen l-ng cc v nhit si ca hai phn ttrn.

III.1.7. Tinh th kim loiBi 77. ng (Cu) kt tinh c dng tinh th lp ph-ng tm din.


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a) Tnh cnh lp ph-ng a(0

) ca mng tinh th v khong cch ngn nht gia haitm ca hai nguyn t ng trong mng, bit rng nguyn t ng c bn knh bng

1,280

.b) Tnh khi l-ng ring d ca Cu theo g/cm3. (Cho Cu = 64).Bi 78. Phn t CuCl kt tinh d-i dng lp ph-ng tm din. Hy biu din mng c s

ca CuCl.a) Tnh s ion Cu+ v Cl - ri suy ra s phn t CuCl cha trong mng tinh thc s.b) Xc nh bn knh ion Cu+.

Cho: d(CuCl) = 4,136 g/cm3 ; rCl = 1,840

A ; Cu = 63,5 ; Cl = 35,5Bi 79. T nhit phng n 1185K st tn ti dng FeE vi cu trc lp ph-ng

tm khi, t 1185K n 1667K dng FeK vi cu trc lp ph-ng tm din. 293K

st c khi l-ng ring d = 7,874g/cm3.a) Hy tnh bn knh ca nguyn t Fe.b) Tnh khi l-ng ring ca st 1250K (b qua nh h-ng khng ng k do s dn

n nhit).Thp l hp kim ca st v cacbon, trong mt s khong trng giacc nguyn tst b chim bi nguyn t cacbon. Trong l luyn thp (l thi) st d nng chykhi cha 4,3% cacbon v khi l-ng. Nu -c lm lnh nhanh th cc nguyn tcacbon vn -c phn tn trong mng l-i lp ph-ng ni tm, hp kim -c gi lmartensite cng v dn. Kch th-cca t bo s ng ca FeEkhng i.

c) Hy tnh s nguyn t trung bnh ca C trong mi t bo s ng ca FeE vi hm

l-ng ca C l 4,3%.d) Hy tnh khi l-ng ring ca martensite. (cho Fe = 55,847; C = 12,011; s N = 6,022.

1023 )

Bi 80. a) Hy v s m t cu trcca mt t bo s ng ca kim c-ng.b) Bit hng s mng a = 3,5

0

. Hy tnh khong cch gia mt nguyn t C v mtnguyn t C lng ging gn nht. Mi nguyn t C nh- vy -c bao quanh bi mynguyn t khong cch ?

c) Hy tnh s nguyn t C trong mt t bo s ng v khi l-ng ring ca kim c-ng.Bi 81.Tinh th NaCl ccu trc lp ph-ng tm mt cacc ion Na+,cn cc ion Cl-chim cc l trng tm mt trong mng c s cacc ion Na+, ngha l c 1 ion Cl-

chim tm ca hnh lp ph-ng. Bit cnh aca mng c s l 5,580

A . Khi l-ngmol ca Na v Cl ln l-t l 22,99 g/mol; 35,45 g/mol.

Tnh :

a) Bn knh ca ion Na+

. b) Khi l-ng ring ca NaCl (tinh th).III.1.9. Bi tp tng hpBi 82p dng thuyt lai ha gii thch kt qu thc nghim xc nh -c BeH2, CO2

u l phn t thng.Bi 83.1) Nhm clorua khi ha tan vo mt s dung mi hoc khi bay hi nhit khng

qu cao th tn ti dng ime (Al2Cl6). nhit cao (7000C) ime b phn li thnh

monome (AlCl3). Vit cng thccu to Liuyt ca phn t ime v monome; cho bit


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kiu lai haca nguyn t nhm, kiu lin kt trong mi phn t; M t hnh hccacc phn t .

2) Phn t HF v phn t H2O c momen l-ng cc, phn t khi gn bng nhau (HF :1,91D , 20v.C ; H2O: 1,84D , 18v.C); nh-ng nhit nng chy ca hiroflorua l -830C thp hn nhiu so vi nhit nng chy ca n-c l 00C, hy gii thch vsao ?

Bi 84.1) Trong s cc phn t v ion: CH2Br2, F-, CH2O, Ca

2+, H3As, (C2H5)2O. Phn t v ion

no c th to lin kt hiro vi phn t n-c ? Hy gii thch v vit s m t shnh thnh lin kt .

2) a) 238U t phn r lin tc thnh mt ng v bn cach. Tng cng c 8 ht E-c phng ra trong qu trnh . Hy gii thch v vit ph-ng trnh phn ng chungca qu trnh ny.

b) Uran ccu hnh electron [ n]5f36d17s2. Nguyn t ny c bao nhiu electron cthn ? C th c mc oxi hacao nht l bao nhiu ?

3) Trong nguyn t hoc ion d-ng t-ng ng c t 2 electron tr ln, electron chuynng trong tr-ng lc -c to ra t ht nhn nguyn t v cc electron khc. Do mi

trng thi ca mt cu hnh electron c mt tr s nng l-ng. Vi nguyn t Bo (s nv in tch ht nhn Z = 5) trng thi c bn c s liu nh- sau:Cu hnh electron Nng l-ng (eV) Cu hnh electron Nng l-ng (eV)

1s1 -340,000 1s22s2 -660,0251s2 -600,848 1s22s22p1 -669,800

1s22s1 -637,874Trong : eV l n v nng l-ng; du - biu th nng l-ng tnh -c khi electroncn chu lc ht ht nhn.

a) Hy trnh by chi tit v kt qu tnh cc tr s nng l-ng ion hac th ccanguyn t Bo theo eV khi dng d kin cho trong bng trn.

b) Hy nu ni dung v gii thch qui lut lin h giacc nng l-ng ion ha

4) Nng l-ng lin kt ca N N bng 163 kJ/mol,ca N | N bng 945 kJ/mol. T 4nguyn t N c th to ra mt phn t N4 t din u hoc 2 phn t N2 thngth-ng. Tr-ng hp no thun li hn ? Hy gii thch.

Lien ket hoa hoc[1]

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