Hoa Hoc (CD PHuc Chat)_Hoa Binh

Embed Size (px)

DESCRIPTION

hay

Citation preview

Cu 1

Chuyn phc cht - nhm GV ha trng THPT chuyn HVT -Ha bnh thc hin

Trong nhng nm gn y ho hc phc cht pht trin mt cch mnh m khng nhng trong nghin cuhn lm m c trong nghin cu ng dng vo cng nghip. Trong cng nghip ho hc, xc tc phc cht lm thay i c bn qui trnh sn xut nhiu ho cht c bn nh axetanehit, axit axetic, v nhiu loi vt liu nh cht do, cao su. Nhng ht nano phc cht chm kim loi ang c nghin cu s dng lm xc tc cho ngnh "ho hc xanh" sao cho n c cc qu trnh sn xut khng gy c hi cho mi trng, cng nh cho vic to lp cc vt liu v c mi vi nhng tnh nng u vit so vi cc vt liu truyn thng...

I. Khi nim phc cht

Phc cht l hp cht to c cc nhm ring bit t cc nguyn t, ion hoc phn t vi nhng c trng sau:

- C mt s phi tr.

- Khng phn ly hon ton trong dung dch.

- C thnh phn phc tp.

Trong c trng th nht l quan trng hn c.

Trong phn t phc cht thng gm hai phn: ion phc hay cn gi l cu ni v cc ion tri du vi ion phc gi l cu ngoi. Cu ni c to thnh bi nguyn t hoc ion kim loi, gi l ion trung tm lin kt trc tip vi cc phn t trung ha hoc ion bao xung quanh n. Cc ion hoc phn t trung ha ny gi l phi t, s phi t bao quanh ion trung tm gi l s phi tr.

V d: K3[Fe(CN)6] th Fe(CN)63- l cu ni, K+ l cu ngoi, CN- l phi t v s phi tr l 6.

II. Phn loi phc cht

Da vo in tch ca ion phc, ngi ta chia phc cht thnh 3 loi:

1. Phc cht cation:

Cc phc cht cation thng c to thnh khi cc phn t trung ha phi tr xung quanh cation.

VD: [Zn(NH3)4]Cl2; [Cr(H2O)6]Cl3; NH4+; [FH2]+; H3O+; ClH2

2. Phc cht anion:

Cc phc cht anion thng c to thnh khi cc anion phi tr xung quanh cation.

VD: K2[BeF4]; Na3[AlF6]; K4[Fe(CN)6]; K3[Fe(CN)6]

3. Phc cht trung ha:

Cc phc cht ny c to thnh khi cc phi t trung ha v cc phi t tch in m phi tr xung cation. cc phc cht trung ha khng c cu ngoi.

VD: [Co(NH3)3 Cl3; [Pt(NH3)4Cl2]; [Fe(NO)]SO4

III- Gii thch lin kt trong phc

(thuyt phi tr ca Vecne)

III-1 Thuyt phi tr:

Nm 1893 Vecne (26 tui) a ra thuyt phi tr. C 3 lun im.

1. a s cc nguyn t u th hin 2 kiu ha tr: ha tr chnh v ha tr ph:

- Ha tr chnh:

- Ha tr ph: .

2. Mi nguyn t cc nguyn t u mun bo ha c hai loi ha tr .

3. Ha tr chnh v ha tr ph u hng n nhng v tr c nh trong khng gian.

VD:

III-2. Mt s khi nim trn c s thuyt Vecne

1. Ion trung tm

Cc nhm c trong thnh phn phc cht sp xp mt cc xc nh xung quanh ion trung tm hay nguyn t to phc, nguyn t hay ion c gi l ion trung tm (nguyn t trung tm).

VD: [Fe(CN)6]4- Fe2+ ion trung tm

Fe(CO)5Feo nguyn t trung tm

2. Phi t (Ligan) (nhm th)

Nhm phn t hay ion sp xp mt cch xc nh xung quanh ion trung tm th c gi l phi t.

[Co(NH3)6]3+NH3 phi t

3. Cu ni:

Ion trung tm v cc phi t to nn cu ni, tng in tch cc thnh phn ca cu ni l in tch ca phc.

Cu ni ca phc c t trong du [ ]n4. Cu ngoi:

Cc ion mang in tch trung ha in tch ca cu ni c gi l cu ngoi.

Ha tr chnh: cu ngoi (cu ni)

Ha tr ph: cu ni.

Trong cu ni ch c mt loi phi t th cc ha tr chnh v ha tr ph tng ng.

5. S phi tr v s phi tr

- Vecne gi s ht cc nguyn t hay ion trung tm v pha mnh l s phi tr.

- S nhm nguyn t hay ion lin kt vi ion trung tm trong cu ni c gi l s phi tr.

- Thc nghim cho ta bit c s phi tr c trng ca mt s ion trung tm:

S phi tr 6: Cr3+; Co3+; Fe2+; Fe3+; Ir3+, Pt4+

S phi tr 4: C4+, B3+, Be2+, V3+, Pt2+, Au3+6. Dung lng phi tr

- Dung lng phi tr ca mt s phi t l s phi tr m n chim c bn cnh ion trung tm.

- Dung lng phi tr bng 1: F-, Cl-, I-, NH3, piridin, H2O, ROH, amin

- Dung lng phi tr bng 2, gi l a phi tr (phi t a rng):

EtyleniaminH2N-CH2-CH2-NH2(k hiu: En)

Anion oxalat C2O42-(COO-)2

IV. Cch gi tn ca phc

1. Theo Vecne

a. Phc cation

- Gi tn cc gc axit bng cch thm o vo ui

- Gi tn phn t trung ha: gi tn thng thng

VD: NH3 ammin, H2O aqu

- S hy lp ch s phi t: i, tri, tetra, penta

i vi cc phi t phc tp: 2 bis; 3 tris; 4 tetrakis

- Nguyn t (ion) trung tm: c gi bng ting la tinh

- ch mc oxi ha ca ion trung tm:

1- thm a

2 thm o

3 thm i

4 thm e

- Tn cu ngoi:

[Ag(NH3)2]NO3 iamminagenta nitrat

[Fe(H2O)4Cl2]Cl iclotetraaqu st (III)clorua

[Co(NH3)4Cl2]Cl iclotetraamincobanti clorua

[PtEn2Cl2](NO3)2 iclobis-etyleniamminplatine nitrat

Tng qut:

Gc axit phi t trung ha ion trung tm cu ngoi

Hy lp

a-o-i-e

Bis

b. Phc anion

Tt c u ging nh tn gi phc anion, ch khc khi gi tn ion trung tm v s oxi ha ca n th thm at vo sau cng.

Na[Au(CN)2] Natri ixianoauraat

K4[Fe(CN)6] Kali hecxaxianoferoat

K3[Fe(CN)6] Kali hecxaxianoferiat

K2[PtCl6] Kali hecxacloro platineat

K[Co(DH)2Cl] Kali icloro-bis-imetylglioximato cobantiat

c. Phc trung ha

Vn tun theo quy lut trn.

Ion trung tm c gi tn thng thng.

[Pt(NH3)2Cl2] icloroiammin platin

2. Danh php quc t

a. Cc nhm m in: thm o

Phi t trung ha gi ng tn: H2O aqu; NH3 amin (phn trn vit l ammin)b. Ion trung tm ca anion phc: tn la tinh + at

cation phc: gi nguyn tn

phc trung ha: gi nguyn tn

c. S oxi ha ion trung tm c ch bng s la m t sau tn gi.

d. S lng phi t: S hy lp: i, tri

phi t phc tp: bis, tris, tetrakis

Tng qut:

Gc axit phi t trung ha ion trung tm

K4[Fe(CN)6] Kali hecxaciano ferat (II)

Ca2[Fe(CN)6] Canxi hexaciano ferat (II)

Na[Co(CO)4] Natri tetracacbonyl cobantat (-I)

K4[Ni(CN)4] Kali tetraciano nikelat (0)

[Fe(H2O)6]SO4Hecxaaqu st (II) sunfat

[Cr(NH3)4Cl]Cliclorotetra crom (III) clorua

[Pt(NH3)4Cl2]Cl2 icloro tetraamin platin (IV) clorua.

[Pt(NH3)2Cl2]icloro iamin platin

[Cu(NH3)4](NO3)2Tetraamin ng (II) nitrat

* Ch : Tn mt s kim loi theo ting La tinh:

Ag: Argentum; Au: Aurum; Co: Cobaltum; Cr: Chromium; Cu: Cuprum; Fe: Ferrum; Pb: Plumbum; Sn: Stannum; Zn: zincum.

Cu to phc cht theo thuyt VB

Cu hnh khng gian ca phc ph thuc vo cc dng lai ha.

Dng lai haCu trcIon trung tm

spng thngAg+, Hg2+

sp3T dinAl3+, Zn2+, Co2+

dsp2Vung phngPd2+, Pt2+, Cu2+, Ni2+, Au3+

d2sp3Bt dinCo3+, Fe3+, Pt4+, Cr3+

Cc ni dung c bn:

1. Lin kt ho hc trong phc cht bao gm cc lin kt 2 electron, cc phi t c 2 electron khng phn chia ng vai tr cht cho electron, cc ion trung tm c cc obitan trng ng vai tr cht nhn electron, gia ion trung tm v phi t to thnh lin kt cho-nhn v phn ng to phc c xem nh phn ng axit-baz.

2. S xen ph cng ln th lin kt cng bn. Mun vy, trc khi to thnh lin kt, cc obitan trng ca ion trung tm lai ha vi nhau to thnh cc obitan lai ha tng ng v s phi tr ca ion trung tm bng s obitan lai ha. Kiu lai ha ph thuc vo cu to electron ca ion trung tm v trong mt s trng hp ph thuc vo bn cht ca phi t. Ty thuc vo kiu lai ha ca ion trung tm m phc cht c cu trc ny hay cu trc khc.

Lu :

Cc obitan mun lai ha phi c iu kin:

- Gn nhau v cu hnh khng gian

- Gn nhau v nng lng

VD: dsp2:

d2sp3

3. Khi c obitan d ca ion trung tm tham gia lai ha, trong mt s trng hp, vic lai ha ngoi hay trong ph thuc vo s tng tc gia ion trung tm v phi t: phi t tng tc yu s to ra lai ha ngoi, phi t tng tc mnh s to ra lai ha trong. Mc tng tc gia phi t v ion trung tm gim dn nh sau:

NO2, CO, CN- En > NH3 >Py> SCN- > H2O > OH- > F- > Cl- > Br- > I-.

Mnh

Trung bnh

Yu

Phc cht c s lai ha ngoi th bn phc km bn hn phc cht c s lai ha trong (phc lai ha ngoi c kh nng phn ng cao) v khi lai ha ngoi th mc nng lng ca cc obitan tham gia lai ha (ns, np, nd) khc nhau nhiu hn so vi khi lai ha trong ((n-1)d, ns, np)).

Phc c obitan trng c kh nng phn ng cao.

4. Qu trnh to phc trn c s lin kt ha tr c th chi thnh cc bc sau:

Bc 1: Bit c cu trc ca ion trung tm.

Bc 2: Dng lai ha ca cc obitan ca ion trung tm

Bc 3: Xy dng cu trc ca phc

* c trng cho mc thun t ca mt cht, ngi ta dng mt i lng l momen t (. Momen t lin h vi s electron c thn theo h thc:

(manheton Bo)

trong , n: s electron c thn.

VD 1: K2[NiCl4] ( ( 0

+ ZNi = 28

Ni [Ar]3d84s2

Ni2+ [Ar]3d8

+ Lai ha: ( ( 0 sp3Ion((((((((

Lai ha((((((((

sp3

+ To phc:

((((((((xxxxxxxx

ClClClCl

Chng minh:

VD 1: [FeF6]4- ( ( 0

+ ZFe = 26

Fe [Ar]3d64s2

Ni2+ [Ar]3d6

+ Lai ha: ( ( 0 d2sp3 ( sp3d2Ion((((((

Lai ha((((((

sp3d2

+ To phc:

Ion((((((xxxxxxxxxxxx

FFFFFF

Chng minh:

VD 3: [Fe(CN)6]4- ( ( 0 d2sp3

+ Lai ha: ( ( 0 d2sp3 ( sp3d2

Ion((((((

Lai ha((((((

d2sp3

VD 4: [Ni(CN)4]2- ( = 0 (vung phng)

Ion((((((((

Lai ha((((((((

dsp2

VD 5: [CoCl6]3-

Ion((((((

Lai ha((((((

sp3d2

( = 4,9

VD 6: [Co(CN)6]4-

Ion(((((((

Lai ha(((((((

d2sp3

Kh nng phn ng cao v c 1e c thn lp ngoi cng

VD 7: [V(NH3)6]3+

Ion((

Lai ha((

d2sp3

Kh nng phn ng cao v c 1 obitan trng.

Cu to khng gian - ng phn ca phc

Thng thng ngi ta gp cu hnh khng gian ca phc trn c s phi tr.

Phi tr 2: Dng ng thng: Ag(NH3)+Phi tr 4: T din (4 mt)

Hnh chp

T din Vung phng

Phi tr 4: bt din (hnh qu trm)

1. ng phn hnh hc

Phi tr 2: Khng c ng phn hnh hc

Phi tr 4: * T din khng c ng phn

* Vung phng: + MeA2B2 c 2 dng ng phn

VD: [Pt(NH3)2Cl2]

+ MeABCD c 3 ng phn

Phi tr 6: MeA4B2 c 2 ng phn

+ MeA3B3 c 2 ng phn

+ MeA2B2C2 c 5 ng phn

+ MeABCDEG c 15 ng phn

2. ng phn quang hc

Mt s bi tp v phc chtCu 1Tng hp mt hp cht ca crom. S phn tch nguyn t cho thy rng thnh phn c Cr (27,1%); C (25,2%), H(4,25%) theo khi lng, cn li l oxy.

1. Tm cng thc thc nghim ca hp cht ny.

2. Nu cng thc thc nghim gm mt phn t nc, ligand kia l g? Mc oxy ha ca Cr l bao nhiu?

3. Kho st t tnh cho thy hp cht ny l nghch t, phi gii thch t tnh ca hp cht ny nh th no? V th cu to ph hp ca cht ny. Chtt, 0C(fG0, kJ/mol

NiO1627-72,1

TiO2727-757,8

TiC727-162,6

CO727-200,2

NH327-16,26

Cho: O = 16; Fe = 55,85; As = 74,9;

HDG:1. Cng thc thc nghim CrC4H8O5.

2. T cng thc thc nghim CrC4H8O5, hp cht l [Cr(CH3COO)2(H2O)]. Nh vy, ligand l cc nhm axetat. Do nhm (CH3COO-) c in tch 1 nn mc oxy ha ca Cr l +2.

3. Ion Cr2+ l h d4, ngha l h c 4e thuc obitan d. S phn b 4 electron phi thuc loi spin nng lng cao do ligand yu. Ch yu t ny cho thy [Cr(CH3COO)2(H2O)] c tnh thun t. Tuy nhin t cc kt qa thc nghim, hp cht ny li c tnh nghch t l do hp cht ny dng nh hp c cu to nh sau:

Trong cu to ny, hai nguyn t Cr to lin kt bn, bao gm mt sigma, hai pi v mt delta, vi bc lin kt tng cng l 4. S hnh thnh lin kt bn i hi tt c cc electron thuc obitan d u phi cp i. V vy da theo tnh cht t, hp cht dng nh hp l nghch t.

Cu 2: bn ca cation Au+.

Th tiu chun: Au+/Au c E(1 = 1,68V; Au3+/Au c E(2 = 1,50V

1. Tnh nng cation Au+ ln nht trong dung dch Au3+ 10-3 mol.l-1.

2. Trong dung dch c d anion X-, Au+ to phc AuX2- (hng s khng bn K1). Au3+ to phc AuX4- (hng s khng bn K2), d ion X- c cn bng sau (hng s cn bng l K().

Vit biu thc tnh K( theo K, K1, K2Cho bit: X- = Br-, pK1 = 12, pK2 = 32; X- = CN-, pK1 = 38, pK2 = 56; da vo tnh ton a ra kt lun g?

3. Vng c th tan trong dung dch KCN 1M c bo ho kh oxi, da vo tnh ton hy gii thch hin tng ny.( pH=0 th tiu chun: O2/H2O c E( = 1,23V; HCN c pKa = 9,4)

HDG:1. Au3+ +3e ( Au E= 1,5V

Au++ e ( Au E= 1,68V

Au3++2e ( Au+E0 = = = 1,41V

E > E ( trong dung dch c th xy ra cc phn ng sau:

3Au+(Au3+ + 2Au 298K: lgK = =

([Au+] = = 9,10610-5(mol/l) 2. 3Au+(Au3+ + 2Au

K=

C d X-, tn ti cn bng sau:

3AuX

(AuX + 2X- +2Au

AuX

(Au+ + 2X-

AuX ( Au3++4X-

Suy ra:

X- = Br-(K= 109,122

X- = CN-(K=109,122

+ Khi anion l Br- : Au+ Au3+ v Au

+ Khi anion l CN-: Au3+ v Au Au+

3. KCN ( K+ + CN-

1M 1M

CN- + H2O ( HCN + OH-Ban u 1

Phn ng

Cn bng (1 - )

()

O2 + 4H+ + 4e ( 2H2O

, Au c th tan trong dung dch KCN theo phn ng ha hc sau:

4Au + 8KCN + 2H2O + O2 ( 4K[Au(CN)2] + 4KOH

E = 1,099V (K = 1074,257)

Cu 3:Khi thm ion Co3+ vo nc amoniac xy ra phn ng sau:

Co3+ (aq) + 6 NH3 (aq) (( [ Co(NH3)6]3+ (aq)

Hng s cn bng chung ca phn ng to phc K = 4,5 ( 1033 (mol/L)6.

Trong mt dung dch, nng cn bng ca amoniac l c(NH3 (aq)) = 0,1 mol/l v tng cc nng cn bng ca Co3+ (aq) v [Co(NH3)6]3+ (aq) bng 1 mol/l.

1)

Tnh nng ca Co3+ (aq) trong dung dch ny.

2)

Hng s cn bng chung K ca [Co(NH3)6]2+ (aq) nh hn nhiu,

K = 2,5 ( 104 (mol/l)-6. Tnh t l c(Co2+ (aq))/c([Co(NH3)6]2+ (aq)) trong mt dung dch m nng cn bng ca amoniac l c(NH3 (aq)) = 0,1 mol/L. 3)

Co3+ (aq) phn ng vi nc gii phng kh no? Gii thch.

4)

V sao khng gii phng kh trong dung dch cu a)?

HDG

1

( 2.

3

Theo gi thit:

Co3+ (aq) + e-

Co2+ (aq)

E( = + 1,82V

2H2O + 2e-

H2 (k) + 2OH- (aq)E( = 0,42V ti pH = 7

O2 (k) + 4H+ (aq) + 4e- 2H2O

E( = + 0,82V ti pH = 7

Co3+ phn ng nn phi l cht oxi ha (nhn e), do theo cc phng trnh trn, nu c gii phng kh, bt buc H2O phi nhng electron v gii phng kh O2.

4[Co3+] = 2,2 ( 10-28 mol/L qu nh nn th nh hn th ca (2H2O/O2, 4H+) nn qu trnh oxi ha khng th xy ra c.

Cu 4Ion Fe (SCN)2+ c mu nng bng hoc ln hn 10-5M. Hng s in li ca n l 10-2.

1. Mt dung dch cha vt Fe3+. Thm vo dung dch ny mt lng KSCN n nng 10-2M (coi th tch dung dch khng i). Xc nh nng ti thiu ca Fe3+ dung dch xut hin mu .

2. Mt dung dch cha Ag+ 10-2M v Fe3+ 10-4 M. Thm SCN vo to kt ta AgSCN (coi th tch khng i). Xc nh nng Ag+ cn li trong dung dch khi xut hin mu . Bit TAgSCN = 10-2.

3. Thm 20cm3 dung dch AgNO3 5.10-2M vo 10cm3 dung dch NaCl khng bit nng . Lng d Ag+ c chun bng dung dch KSCN vi s c mt ca Fe3+ im tng ng (khi bt u xut hin mu ) c quan st thy khi thm 6cm3 dung dch KSCN 10-1M. Tnh nng ca dung dch NaCl.

HDG

a/ Xt CB

Khi c mu th x = 10-5M thay vo ta c :

b/ Khi xut hin mu th th

Khi ta c :

c/ Theo phn trn

(ban u)

CU 5 : Cu hnh electron ca nguyn t M trng thi c bn ch ra rng: M c 4 lp electron, s electron c thn ca M l 3.

a. Da vo cc d liu trn cho bit M c th l cc nguyn t no.

b. M to c ion phc c cng thc (M(NH3)6(3+, php o momen t ch ra rng ion ny l nghch t.

- Cho bit tn gi ca (M(NH3)6(Cl3

- Cho bit trng thi lai ho ca M trong ion phc trn v ch ra dng hnh hc ca ion phc ny.

HDG :V c 4 lp in t do vy phn lp cui cng trong phn b in t ch c th l 4S, 3d, 4P.

V c 3 in t c thn do vy, phn lp cui cng ch c th l

3d3 ( Cu hnh hon chnh 1S2 2S2 2P6 3S2 3P6 3d3 4S2 Nguyn t 23V

3d7 ( Cu hnh hon chnh 1S2 2S2 2P6 3S2 3P6 3d7 4S2 Nguyn t 27Co

3P3 ( Cu hnh hon chnh 1S2 2S2 2P6 3S2 3P6 3d10 4S2 4P3 Nguyn t 33As

Hnh dng phn t bt din:

Cu 6: Phc [Fe(CN)6]4- c nng lng tch l 394,2 kJ/mol, phc [Fe(H2O)6]2+ c nng lng tch l 124,2 kJ/mol v nng lng ghp electron l 210,3 kJ/mol.

a) Hy v gin nng lng ca hai phc trn v cho bit phc no l phc spin cao, phc no l phc spin thp?

b) Hi vi s kch thch electron t t2g n eg th phc [Fe(CN)6]4- hp th nh sng c bc sng ( bng bao nhiu.

HDG:Cc phc [Fe(CN)6]4- v [Fe(H2O)6]2+ u l phc bt din. Trong phc [Fe(CN)6]4- c nng lng tch (() > nng lng ghp electron nn phc ny c gin nng lng nh sau:

Trong gin trn tng spin S = 0 v l phc spin thp.

Trong phc [Fe(H2O6)]2+ c nng lng tch thp hn nng lng ghp electron nn phc ny c gin nng lng nh sau:

Trong gin trn tng spin S = 4 x 1/2 = 2 v l phc spin cao.

b) ( = = 3,034.10-7 m hay 3034

Cu 7: 1. Cho X l mui st sunfat khan c 36,84% st v khi lng.

a) Xc nh cng thc ha hc ca X.

b) Hon thnh phng trnh ha hc theo s :

2. Bng di sng ca bc x b hp th v mu nhn thy

Mu ca bc x b hp thBc sng ca bc x b hp th (nm)Mu trng thy cht

(mu ph)

Tm400-424Vng lc

Xanh chm424-480Vng

Lam480-500Da cam

Lc500-575 ta

Vng575-585Tm

Da cam585-647Lam

ta647-710Lc

HDG:

1. a) X l FeSO4

b) (1) FeSO4 + 6KCN K4[Fe(CN)6] + K2SO4 (2) K4[Fe(CN)6] + Cl2 K3[Fe(CN)6] + 2KCN

(3) 4K3[Fe(CN)6] + 4KOHc, nng K4[Fe(CN)6] + O2 + 2H2O

2.

* Ion phc [Mn(H2O)6]3+:

= 0,476.10-6 (m) = 476 nm.

Ion phc [Mn(H2O)6]3+ hp th mu xanh chm nn hp cht Mn(III) trong nc c mu vng.

* Ion phc [Rh(H2O)6]3+:

= 0,371.10-6 (m) = 371 nm.

Ion phc [Rh(H2O)6]3+ hp th bc x c = 371 nm ngoi vng nhn thy nn hp cht Rh(III) trong nc khng c mu.Cu 8:Cho 3 hp cht khc nhau ca Cr(III) vi nc v ion Clo Cl-, c cng thnh phn 19,51% Cr; 40,57% H2O v 39,92% Cl.

+ Hp cht th nht c mu tm, tan nhanh trong nc cho ion phc c in tch 3+ v 3 ion Cl-. Tt c cc ion ny kt ta ngay thnh AgCl khi thm AgNO3 vo dung dch.

+ Hp cht th 2 c mu xanh, tan nhanh trong nc cho ion phc c in tch 2+ v 2 ion Cl-. C 2 ion ny u kt ta cho AgCl.

+ Hp cht th 3 c mu lc, tan nhanh trong nc cho ion phc c in tch 1+ v ion Cl-. Ion ny cho kt ta vi AgCl.

Hy vit cu to, gi tn v v cu trc ca ion phc nu trn.

HDG:Cc phc cht c xt trong chng trnh ph thng thng l phc ch n nhn. V vy, nu gi thit rng trong phn t ca phc cht c xt ch c mt nguyn t Cr (M=52) th s nguyn t Cl v s phn t nc s l:

- S nguyn t Cl (m) bng:

- S phn t nc (n) bng:

Nh vy, CTPT ca phc cht l CrCl3.6H2O

T cc lun c sau:

- Cr3+ thng c 6 phi tr

- Cl- v nc u c th ng vai tr l phi t to phc vi Cr3+

- Lin kt Cr-Cl trong cu ni ca phc cht kh bn, lm cho Cl- trong cu ni ca phc cht khng phn ly thnh ion t do trong dung dch

- Cc d kin ca bi

C th a ra gi thit v thnh phn ca 3 phc cht nh sau:

(1)[Cr(H2O)6]Cl3 ; (2) [Cr(H2O)5Cl2]Cl2.H2O ; (3) [Cr(H2O)4Cl2]Cl.2H2O

Khi phng trnh in ly ca cc phc cht trong dung dch c biu din nh sau:

Phc cht (1): [Cr(H2O)6]Cl3 [Cr(H2O)6]3+ + 3Cl-Phc cht (2): [Cr(H2O)5Cl]Cl2 [Cr(H2O)5Cl]2+ + 2Cl-

Phc cht (3): [Cr(H2O)4Cl2]Cl [Cr(H2O)4Cl2]+ + Cl-Cc ion Cl- nm cu ngoi b phn ly thnh ion t do trong dung dch do tc dng vi AgNO3 cho kt ta AgCl.

Tn ca cc ion phc v cu trc tng ng ca chng nh sau:

[Cr(H2O)6]3+ [Cr(H2O)5Cl]2+ [Cr(H2O)4Cl2]+

Hexaaqu Crom (III) Clopentaaqucrom (III) iclotetraaqucrom (III)

Cu 9 1.Cho bit dng hnh hc ca cc ion sau: [Ni(CN)4]2-; [FeF6]3-. Hy cho bit cc ion trn c tnh thun t hay nghch t? Gii thch? 2 Gi tn v v cc cu trc lp th cho cc ion phc ca coban sau: [CoCl2(NH3)4]+ v [CoCl3(CN)3]3-. HDG1.

Cu hnh electron ca Ni2+: [Ar]3d8 Xt phc [Ni(CN)4]2-:

CN- l phi t trng mnh, dn n ion Ni2+ trng thi kch thch:

( Ni2+ trng thi lai ha dsp2

( [Ni(CN)4]2- c dng vung phng v ion trung tm Ni2+ khng cn electron c thn, do ion [Ni(CN)4]2- c tnh nghch t.

Xt phc [FeF6]3-:

Cu hnh electron ca Fe3+: [Ar]3d5F- l phi t trng yu

( Fe3+ trng thi lai ha sp3d2

( [FeF6]3- c dng bt din u v ion trung tm Fe3+ cn 5 electron c thn ( c tnh thun t.

2.

- Tn ca cc ion phc:

iclorotetraamincoban (III): [CoCl2(NH3)4]+

Triclorotrixianocobanat (III): [CoCl3(CN)3]3-.

- Cu trc lp th:

Bi 10.1. S dng thuyt lin kt ha tr (VB) gii thch dng hnh hc, t tnh ca cc phc cht sau:[Ni(CN)4]2-, [NiCl4]2-, [Ni(CO)4]. Cho C (Z=6), N (Z=7), O (Z=8), Ni (Z=28), Cl (Z=17).

2. Ha tan 2,00 gam mui CrCl3.6H20 vo nc, sau thm lng d dung dch AgNO3 v lc nhanh kt ta AgCl cn c 2,1525 gam. Cho bit mui crom ni trn tn ti di dng phc cht. a) Hy xc nh cng thc ca phc cht .

b) Hy xc nh cu trc (trng thi lai ha, dng hnh hc) v nu t tnh ca phc cht trn.

HDG:

1.

Ni : 3d84s2 ; Ni2+ : 3d8

Ni2+ :

Phc [Ni (CN)4]2- : CN- l phi t nhn ( ( to trng mnh ( dn electron d ( to phc vung phng vi lai ha dsp2 . Spin thp (S = 0 ). Nghch t

Phc [NiCl4]2- : Cl- l phi t cho ( ( to trng yu ( khng dn p electron d c ( to phc t din vi lai ha sp3 . Spin thp (S = 1 ). Thun t

Ni : 3d84s2

Phc [Ni(CO)4] : CO l phi t nhn ( ( to trng mnh ( dn electron 4s vo 3d ( to obitan 4s,3d trng ( lai ha sp3 , phc t din. Spin thp (S = 0). Nghich t

2. a.

n(AgCl) = (2,1525:143,5) = 0,015; n(CrCl3 . 6H2O) = (2:266,5) = 7,5.10-3n(Cl- to phc) = 3(7,5.10-3) - 0,015 = 7,5.10-3

Trong phn t phc cht t l mol Cl: Cr3+ = (7,5.10-3) : (7,5.10-3) = 1:1

Cng thc ca phc: (Cr(H2O)5Cl(2+

b. Cr3+ (1s2 2s2 2p6 3s2 3p6 3d3) ( Cr3+ : [Ar] 3d3

Cu 11:

Cho 3 hp cht khc nhau ca Cr(III) vi nc v ion Clo Cl-, c cng thnh phn 19,51% Cr; 40,57% H2O v 39,92% Cl.

+ Hp cht th nht c mu tm, tan nhanh trong nc cho ion phc c in tch 3+ v 3 ion Cl-. Tt c cc ion ny kt ta ngay thnh AgCl khi thm AgNO3 vo dung dch.

+ Hp cht th 2 c mu xanh, tan nhanh trong nc cho ion phc c in tch 2+ v 2 ion Cl-. C 2 ion ny u kt ta cho AgCl.

+ Hp cht th 3 c mu lc, tan nhanh trong nc cho ion phc c in tch 1+ v ion Cl-. Ion ny cho kt ta vi AgCl.

Hy vit cu to, gi tn v v cu trc ca ion phc nu trn.

HDG

Cc phc cht c xt trong chng trnh ph thng thng l phc ch n nhn. V vy, nu gi thit rng trong phn t ca phc cht c xt ch c mt nguyn t Cr (M=52) th s nguyn t Cl v s phn t nc s l:

- S nguyn t Cl (m) bng:

- S phn t nc (n) bng:

Nh vy, CTPT ca phc cht l CrCl3.6H2O

T cc lun c sau:

- Cr3+ thng c 6 phi tr

- Cl- v nc u c th ng vai tr l phi t to phc vi Cr3+

- Lin kt Cr-Cl trong cu ni ca phc cht kh bn, lm cho Cl- trong cu ni ca phc cht khng phn ly thnh ion t do trong dung dch

- Cc d kin ca bi

C th a ra gi thit v thnh phn ca 3 phc cht nh sau:

(1)[Cr(H2O)6]Cl3 ; (2) [Cr(H2O)5Cl2]Cl2.H2O ; (3) [Cr(H2O)4Cl2]Cl.2H2O

Khi phng trnh in ly ca cc phc cht trong dung dch c biu din nh sau:

Phc cht (1): [Cr(H2O)6]Cl3 [Cr(H2O)6]3+ + 3Cl-Phc cht (2): [Cr(H2O)5Cl]Cl2 [Cr(H2O)5Cl]2+ + 2Cl-

Phc cht (3): [Cr(H2O)4Cl2]Cl [Cr(H2O)4Cl2]+ + Cl-Cc ion Cl- nm cu ngoi b phn ly thnh ion t do trong dung dch do tc dng vi AgNO3 cho kt ta AgCl.

Tn ca cc ion phc v cu trc tng ng ca chng nh sau:

[Cr(H2O)6]3+ [Cr(H2O)5Cl]2+ [Cr(H2O)4Cl2]+

Hexaaqu Crom (III) Clopentaaqucrom (III) iclotetraaqucrom (III)

Cu 12:

Cho bit ion phc Co(III) c cu trc bt din.

1. V tt c cc ng phn ca [Co(NH3)Br(en)2]2+ (en: etyleniamin)

2. Nhng ion phc v ng trong nhng ng mu ring t trn mt ci cn. y cc ion phc c mt nam chm in vy quanh. Khi kch hot nam chm in th khi lng ca tng ln cn khi lng ca khng b nh hng g. Gii thch.Cu 13: Vit cng thc dng cis v trans ca ion phc bt din [Co(NH4)4Cl2]+. Nhn xt v v tr tng i ca 2 nguyn t Cl i vi nguyn t Co trung tm

Cu 14: Phim en trng cha lp ph bc bromua trn nn l xenluloz axetat.

1. Vit phn ng quang ha xy ra khi chiu nh sng vo lp AgBr ph trn phim.

2. Trong qu trnh ny th lng AgBr khng c chiu sng s b ra bng cch cho to phc bi dung dch natri thiosunfat. Vit phng trnh phn ng.

3. Ta c th thu hi bc t dung dch nc thi bng cch thm ion xianua vo, tip theo l km. Vit cc phn ng xy ra.

HDG:

1. Phn ng:

2. AgBr(r) + 2Na2S2O3 Na3[Ag(S2O3)2] + NaBr 3.

Cu 15: Mt vi tnh cht ca mt hp cht v c cha bit A c lit k di y:

A l mt cht rn mu trng hi vng, d chy ra v thng hoa khi un nng. A c KLPT l 266.

A phn ng mnh lit vi nc cho dung dch B.

Khi mt dung dch hn hp gm NH4OH v NH4Cl c thm vo dung dch B th nhn c kt ta keo mu trng.

Mt mu dung dch B phn ng vi dung dch hn hp nitric axit v bc nitrat cho kt ta vn cc mu trng C. Kt ta trng ny nhanh chng tan i khi thm vo dung dch NH4OH mc d khi ta cho d NH4OH th li xut hin kt ta trng D.

Kt ta D c lc v ho tan trong NaOH thu c dung dch trong sut E.

Khi cho kh CO2 li qua dung dch E th li sinh ra kt ta D.

Cht A ho tan khng in ly trong ete khng ln nc. Khi dung dch ny phn ng vi LiH th s to thnh sn phm F. Nu dng d LiH th F s chuyn thnh G.

a. Xc nh cht A.

b. Xc nh cc cht t B n G v vit tt c cc phng trnh phn ng xy ra.

HDG:

a. Trong bc th ba ca php phn tch ta thu c kt ta trng keo, iu ny chng t rng dung dch B c cha Al3+ v dung dch B cng to kt ta trng vi AgNO3, kt ta ny tan i khi ta thm NH4OH vo chng t rng dung dch B c cha Cl-. Vy cht A s l Al2Cl6 (MA = 266).

b. Cc phn ng xy ra:

Al2Cl6 + 12H2O = 2[Al(H2O)6]3+ + 6Cl-6AgNO3 + 6Cl- = 6AgCl + 6NO3-AgCl + 2NH4OH = [Ag(NH3)2]+Cl- + H2O

Al3+ + 3NH4OH = Al(OH)3 + 3NH4+Al(OH)3 + NaOH = Na+[Al(OH)4-]

[Al(OH)4]- + CO2 = Al(OH)3 + HCO3-Al2Cl6 + LiH = (AlH3)n + LiHd = LiAlH4

Cu 16: Nu phng php ha hc tch:

b. Kh N2 ra khi kh NO

c. Ion Be2+ ra khi ion Al3+ trong dung dch mui nitrat ca chng. Nu c s khoa hc ca phng php tch dng.

HDG:

1. Cho qua dd FeSO4, NO b hp th, N2 bay ra: FeSO4 + NO Fe[NO]SO4 un nng dd li c NO

2. Cho Na2CO3 n d vo dung dch. Al3+ tch ra di dng Al(OH)3 cn Be2+ cn li di dng [Be(CO3)2]2-. Ha tan Al(OH)3 vo HNO3 ly li Al3+. Axit ha dung dch ly li Be2+Al3+ + 3 + 3H2O Al(OH)3 + 3CO2 Be2+ + 2 [Be(CO3)2]2- tan

Al(OH)3 + 3H+ Al3+ + 3H2O [Be(CO3)2]2- + 4H+ Be2+ + 2CO2 + 2H2O

C s ca phng php ny l: Ion Be2+ c bn knh b c kh nng to phc vi ion cacbonat cn Al3+ th khng c kh nng ny

Cu 17: 1. Ti sao ion phc spin thp [Co(NH3)6]3+ li c mu. Gii thch da vo . Cho bit: .

Tnh c: . S hp th nh sng nm trong ph nhn thy nn c mu. Cu 18: Hng s bn tng ca ion phc [Cu(NH3)4]2+ l ti 25oC

a. Tnh nng Cu2+ khi cn bng nu nng ban u ca Cu2+ l 5.10-3M v ca NH3 l 1M

b. Xt: . Tnh ca phn ng trn

c. Xt: .

Trong : Trien l Trietilentetramin H2NCH2CH2NHCH2CH2NHCH2CH2NH2, en l etileniamin H2NCH2CH2NH2. Vit cng thc cu to 2 ion phc trn v gii thch s khc nhau gia hai gi tr entropi trn

Cu 19. Ion phc [Mn(H2O)6]3+ c nng lng tch = 250,5 kJ/mol.

Ion phc [Rh(H2O)6]3+ c nng lng tch = 321,6 kJ/mol.

Hi hp cht Mn(III), Rh(III) trong dung dch c mu g?

Cho: hng s Plack h = 6,6.10-34 J.s; tc nh sng c = 3,0.108 m/s

Bng di sng ca bc x b hp th v mu nhn thy

Mu ca bc x b hp thBc sng ca bc x b hp th (nm)Mu trng thy cht

(mu ph)

Tm400-424Vng lc

Xanh chm424-480Vng

Lam480-500Da cam

Lc500-575 ta

Vng575-585Tm

Da cam585-647Lam

ta647-710Lc

HDG:

* Ion phc [Mn(H2O)6]3+:

= 0,476.10-6 (m) = 476 nm.

Ion phc [Mn(H2O)6]3+ hp th mu xanh chm nn hp cht Mn(III) trong nc c mu vng.

* Ion phc [Rh(H2O)6]3+:

= 0,371.10-6 (m) = 371 nm.

Ion phc [Rh(H2O)6]3+ hp th bc x c = 371 nm ngoi vng nhn thy nn hp cht Rh(III) trong nc khng c mu

Cu 20. OLYMPIC HA HC QUC T LN TH 31:

Mt dung dch cha 530mmol Na2S2O3 v mt lng cha xc nh KI. Khi dung dch ny c chun vi AgNO3 th dng c 20,0mmol AgNO3 trc khi bt u vn c v AgI kt ta. C bao nhiu mmol KI?. Bit th tch sau cng l 200mL.

Ag(S2O3)23- Ag+ + 2S2O32-(aq)

Kd = 6,0.10-14.

AgI(r) Ag+(aq) + I-(aq)

T = 8,5.10-17.

HDG:a) Do hng s to phc ca Ag(S2O3)23-, Kf = (Kd)-1 = 1,667.1013 l rt ln nn hu ht Ag+ thm vo s to phc vi S2O32- v:

[Ag(S2O3)23-] = 0,100M

s mmol S2O32- t do = 530 (2.20) = 490mmol.

[S2O32-] = 2,450M

Nng ion Ag+ t do c tnh t Kd

Ag+ + I- AgI

T = [Ag+][I-] = 8,5.10-17( [I-] = 8,5.10-2M

mmol KI = 17,0mmol.

Cu 21. OLYMPIC HA HC QUC T LN TH 32:

Cadimi l mt trong nhng kim loi rt c c tm thy vi nng cao trong cht thi t s luyn km, m in v x l nc thi. Ht phi cadimi dng ht nh s nhanh chng nh hng n h h hp ri sau l thn. Cadimi cho thy s cnh tranh vi km ti cc vng hot ng ca enzym.

Cadimi to thnh hydroxit hi kh tan l Cd(OH)2.

a) Hy tnh tan ca Cd(OH)2 trong nc nguyn cht (b qua cn bng t proton phn)

b) Hy tnh tan ca Cd(OH)2 trong dung dch NaOH(aq) 0,010M

Ion Cd2+ c i lc mnh vi ion CN-:

Cd2+(aq) + CN-(aq) Cd(CN)+(aq)

K1 = 105,48M-1.

Cd(CN)+(aq) + CN-(aq) Cd(CN)2(aq)

K2 = 105,12M-1.

Cd(CN)2(aq) + CN-(aq) Cd(CN)3-(aq)

K3 = 104,63M-1.

Cd(CN)3-(aq) + CN-(aq) Cd(CN)42-(aq) K4 = 103,65M-1.

c) Hy tnh tan ca Cd(OH)2 trong nc c cha ion CN-. Nng cn bng l [CN-]=1,00.10-3M

d) Gi thit rng ch to thnh phc Cd(CN)42-, hy tnh phn trm sai lch tan so vi tan tm c cu c.

Bit T(Cd(OH)2) = 5,9.10-15M3.

HDG:a) S = 1,14.10-5M

b) S = 5,9.10-11M

c) S = 0,5[OH-] = C(Cd)

C(Cd) = [Cd2+] + [Cd(CN)+] + [Cd(CN)2] + [Cd(CN)3-] + [Cd(CN)42-]

0,5[OH-] = [Cd2+](1 + K1[CN-] + K1K2[CN-]2 + K1K2K3[CN-]3 + K1K2K3K4 [CN-]4)

[OH-] = [2.T(1 + K1[CN-] + K1K2[CN-]2 + K1K2K3[CN-]3 + K1K2K3K4 [CN-]4)]3/2

= 4,79.10-3M

S = 2,4.10-3M

d) [OH-] = [2.T.(1 + K1K2K3K4 [CN-]4)]3/2 = 4,47.10-3M

S = 2,24.10-3M

Phn trm sai lch = 6,7%

Cu 22. OLYMPIC HA HC BUNGARI 1998:

Bc clorua d dng ho tan trong dung dch amoniac trong nc v to ion phc:

AgCl(r) + 2NH3 [Ag(NH3)2]+ + Cl-.

a) Mt lt dung dch amoniac 1M h tan c bao nhiu gam AgCl? Bit:

AgCl(r) Ag+ + Cl-

T = 1,8.10-10.

[Ag(NH3)2]+ Ag+ + 2NH3

K = 1,7.10-7.

b) Xc nh tch s tan T ca AgBr. Bit rng 0,54g AgBr c th tan c trong dung dch amoniac 1M.

HDG:a) Ta c:

V [Ag+]