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7/28/2019 L thuyt Ha v c

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TRNG TRUNG HC PH THNGTAM PH

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TN HC SINH:

L THUYT HA

V C 12


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GV :Nguyn Mnh Ton Trang - 2 - L thuyt ha v c 12

GIO VIN: NGUYN MNH TON

CHNG 5: I CNG V KIM LOI

Bi s 1: V TR CA KIM LOI TRONG BNG H THNG TUN HON

I- V TR CA KIM LOI TRONG BNG H THNG TUN HON CU TO V TNHCHT CA KIM LOI

+ Trong bng HTTH, cc nguyn t kim loi c mt : Nhm IA (tr H) v IIA gi l nhng nguyn t s. Nhm IIA (tr B) v mt phn ca cc nhm IVA, VA, VIA gi l nhng

nguyn t p. Nhm B (t IB n VIIIB) gi l nhng nguyn t d. H lantan v actini, gi l nhng nguyn t f c xp thnh 2 hng cui

bng.

II- CU TO NGUYN T KIM LOI

1. Cu to+ Hu ht nguyn t kim loi u c t electron lp ngoi cng (1, 2 hoc

3e).+ Trong mt chu k, nguyn t kim loi c bn knh nguyn t ln hn v

in tch ht nhn nh hn so vi nguyn t phi kim.+ nhit thng, cc nguyn t kim loi u th rn (tr Hg th

lng) v c cu to tinh th.+ Trong tinh th kim loi gm c:

nguyn t kim loi ion kim loi cc electron ha tr (electron t do). Cc electron ha tr lin kt

yu vi ht nhn nn d tch khi nguyn t v chuyn ng t do trong mng tinh th.

2. Lin kt kim loi

+ trng thi lng v rn, cc nguyn t kim loi lin kt vi nhau bng mtkiu lin kt gi l lin kt kim loi. Lin kt kim loi c hnh thnh gia nguyn t v ion kimloi trong mng tinh th do s tham gia ca cc electron t do.

Bi s 2: TNH CHT CA KIM LOI DY IN HA CA KIM LOI

I- TNH CHT VT L CA KIM LOI

1. Tnh cht vt l chung ca kim loi

+ nhit thng, kim loi c mt s tnh cht vt l chung l: tnh do,tnh dn in, tnh dn nhit v nh kim.

+ Tnh cht vt l chung ca kim loi du gy nn bi s c mt ca ccelectron t do trong mng tinh th kim loi.

a) Tnh do

+ Tnh do c sp xp nh sau: Au, Ag, Al, Cu, Sn,..

b) Tnh dn in

+ Tnh dn in c sp xp nh sau: Ag, Cu, Au, Al, Fe,..

Ch : Nhit cng cao, tnh tnh dn in cng gim.

GV :Nguyn Mnh Ton Trang - 2- L thuyt ha v c 12


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c) Tnh dn nhit

+ Tnh dn in c sp xp nh sau: Ag, Cu, Al, Fe,.. ni chung, kimloi c tnh dn in tt th dn nhit cng tt.

d) nh kim

+ L do cc electron t do trong kim loi phn x tt vi nhng tia sng c bc sng.

2. Tnh cht vt l ring ca kim loi+ Tnh cht vt l ring ca kim loi quan trng nht l : khi lng ring (D),nhit nng chy v tnh cng.

Kim loi nh nht l Li(D = 0,5 g/cm3), kim loi nng nht l Os (D = 22,6 g/cm3).

Kim loi c nhit nng chy thp nht l Hg(-39oC), kim loi c nhit nngchy cao nht l W(+ 3410oC).

Kim loi mm nht l K (kali), kim loi cng nht l Cr (crom).

II- DY IN HA KIM LOI

1. Khi nim v cp oxi ha kh ca kim loi

Tnh oxi ha tng dn

K+ Na+ Ba2+ Ca2+ Mg2+ Al3+ Zn2+ Cr2+ Fe2+ Ni2+ Sn2+ Pb2+H+ Cu2+ Fe3+ Hg2+ Ag+ Pt2+ Au3+

K Na Ba Ca Mg Al Zn Cr Fe Ni Sn Pb H2 Cu Fe2+ Hg Ag Pt Au

Tnh kh gim dn

Th d:Zn + 2AgNO3 Zn(NO3)2 + 2Ag hay: Zn + 2Ag+ Zn2+ + 2Ag

Fe(NO3)2 + AgNO3 Fe(NO3)3 + Ag hay: Fe2+ + Ag+ Fe3+ + Ag

Fe + 2FeCl3 3FeCl2 hay: Fe + 2Fe3+ 3Fe2+

BI S 3: HP KIM

I- KHI NIM V HP KIM+ Hp kim l vt liu kim loi c cha mt kim loi c bn v mt s kim loi hoc phikim khc.Th d:

Thp (Fe C)

Hp kim khng b n mn (thp inoc): Fe Cr Mn

Hp kim siu cng: (W Co), (Co Cr W Fe) Vng ty: (Au Ag Cu)

I- TNH CHT CA HP KIM

+ Tnh cht ca hp kim ph thuc vo thnh phn cc n cht tham gia cu to tinhth ca hp kim.

Tnh cht ha hc ca hp kim, nhn chung tng t nh cc n chttham gia to thnh hp kim.



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Tnh cht vt l ca hp kim, li khc nhiu so vi cc n cht tham gia tothnh hp kim.

Ch : Trong thc t, hp kim c x dng nhiu hn kim loi nguyn cht.

BI S 4: S N MN KIM LOI

I- KHI NIM V N MN KIM LOI

+n mn kim loi l s ph hy kim loi hoc hp kim do tc dng ca cc cht trongmi trng xung quanh.

y l mt qu trnh ha hc hoc qu trnh in ha, trong kim loi b oxi ha thnh iondng.

II- CC DNG N MN KIM LOI

+ n mn ha hcThng thng c 2 dng chnh:

+ n mn in ha hc1. n mn ha hc

+ n mn ha hc l qu trnh oxi ha kh, trong cc electron ca kim loichuyn trc tip n cc cht trong mi trng.

Th d: Chi tit kim loi ca my mc trong cc nh my ha cht, l t, l hi, ng c ttrong, tip xc vi ha cht hoc hi nc nhit cao (nhit cng cao, kim loi b nmn cng nhanh).

2. n mn in ha hca) khi nim

+ n mn in ha hc l qu trnh oxi ha - kh, trong kim loi b n mn do tcdng ca dung dch cht in li v to nn dng electron chuyn di t cc m n cc dng.Th d:

b) n mn in ha hc hp kim ca st trong khng kh mTh d:

+ S n mn gang hoc thp (Fe C) trong khng kh m


M0 Mn+ + ne(kim loi) (ion kim loi)

Cc (-) anot Cc (+) catot)+ Zn b n mn + To kh H2

Zn b oxi ha (H+ ca dung dch H2SO4 b kh)Zn Zn2+ + 2e 2H+ + 2e H2


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c) iu kin xy ra n mn in ha hc

+ Phi 3 iu kin sau mi xy ra n mn in ha hc:

Cc in cc phi khc nhau v bn cht (2 kim loi khc nhau hoc kim loi vi phikim.

Cc in cc phi tip xc trc tip hoc gin tip vi nhau qua dy dn.

Cc in cc cng tip xc vi dung dch cht in li.

Ch : Trong thc t qu trnh n mn kim loi b xy ra rt phc tp, thng xy ra n mnng thi c 2 loi trn.

III. CHNG N MN KIM LOI

+ C nhiu cch chng n mn ha hc nhng c 2 phng php thng dng l:phng php bo v b mt v phng php in ha.

1. Phng php bo v b mt

+ Dng nhng cht bn vng i vi mi trng ph bn ngoi mtnhng vt bng kim loi nh: bi du m, s, m, trng men,..

Th d: St ty (st trng thic), tn (st trng km), inoc (st m niken hay crom).

2. Phng php in ha

+ Ni kim loi cn c bo v vi mt kim loi hot ng hn to thnhpin in ha.

Th d:

+ bo v tu bin lm bng thp, ngi ta gn vo mt ngoi ca v tu (phnchm trong nc) nhng khi km. Kt qu l km b nc bin n mn thay cho v tu.

+ Tn (st trng km), km b n mn thay cho st.

BI S 5: IU CH KIM LOI

S iu ch kim loi


Cc (-) anot Cc (+) catot)+ Fe b n mn + Oxi trong nc b kh

Fe b oxi ha O2 + 2H2O + 4e OH-

Fe Fe2+ + 2e

cui cng to g st c cng thc Fe2O3.nH2O


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(kim loi tnh kh mnh)

K Na Ba Ca Mg Zn Fe Ni Sn Pb H Cu Hg Ag Pt Au

(kloi tnh kh trung bnh) (kim loi tnh kh yu)

Dng hp cht muihalogenua (vd: NaCl)

(in phn nng chy)

Phng php nhit luyn:Oxit kim loi+ cht kh: (CO, C, Al, H2) nhit cao.

Phng php thy luynKim loi + dung dch mui

Phng php in phn dung dch- in phn dung dch mui


I- NGUYN TC CHUNG IU CH KIM LOI

+ Trong t nhin a s kim loi u nm dng hp cht (dng ion dng). Do nguyn tc chung iu ch kim loi l kh ion kim loi trong hp cht thnh kim loi.

II- CC PHNG PHP IU CH KIM LOI

1. Phng php nhit luyn

+ Dng iu ch nhng kim loi c hot ng trung bnh v yu (t Zn tr i).

Phng php: Dng cc cht kh (C, CO, Al, H2) khion kim loi trong hp cht oxitthnhkim loi nhit cao.Th d:

ZnO + H2ot Zn + H2O

PbO + COot

Pb + CO2

Fe2O3 + 2Alot 2Fe + Al2O3

CuO + Cot Cu + CO2

2. Phng php thy luyn

+ Dng iu ch nhng kim loi c tnh kh yu (ng sau hiro).

Phng php: Dng kim loi c tnh kh mnh hn (Fe, Zn, ..) kh ion kim loi trong dungdch mui.

Th d: Fe + CuSO4 FeSO4 + Cu

Cu + 2AgNO3Cu(NO3)2 + 2Ag

3. Phng php in phn


Mn+ + ne M0

(ion kim loi) (kim loi)


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a) in phn nng chy

+ Dng iu ch kim loi c tnh kh mnh (t K Al).Phng php: Dng dng in in phn hp cht muinng chy (ch yu l mui clorua)ca ion kim loi (ring Al dng oxit kim loi Al2O3).

Ch : in phn nng chy khng c s tham gia ca nc. Th d 1:

in phn nng chy Al2O3; Al2O3 2Al3+

+ 3O

2-

+ S in phn:cc catot (-) cc anot (+)

+ Xy ra s khion Al3+ + Xy ra s oxi ha ion O2-

Al3+ + 3e 2Al 2O2-O2 + 4e

+ Phng trnh in phn: Al2O3 pnc 2Al + 3/2O2 Ta iu ch c kim loi Al

Th d 2: in phn nng chy NaCl; NaCl Na+ + Cl-


+ Xy ra s khion Na+ + Xy ra s oxi ha ion Cl-

Na+ + 1e Na 2Cl- Cl2 + 2e

+ Phng trnh in phn: NaCl pnc Na + 1/2Cl2

Ta iu ch c kim loi Na Th d 3: in phn nng chy MgCl2; MgCl2 Mg2+ + 2Cl-


+ Xy ra s khion Mg2+ + Xy ra s oxi ha ion Cl-

Mg2+ + 2e Mg 2Cl- Cl2 + 2e

+ Phng trnh in phn: MgCl2 pnc Mg + Cl2 Ta iu ch c kim loi Mg

b) in phn dung dch

+ Dng iu ch kim loi c tnh kh trung bnh v yu (t Zn )Phng php: Dng dng in in phn dung dch mui (Cl-, SO42-, NO3-,..) ca ion kim loi.

Ch : in phn dung dch c s c mt ca nc.

C ch in phn dung dchCl-, Br-

+ Trong dung dch th: Mui ion (+) kim loi + ion (-) gc axitSO42-, NO3-


cc catot (-)

+ Xy ra qu trnh kh

Trng hp 1: Khi ion kim loi ngsau Al ion kim loi u tin b kh trc.

Mn+ + ne M

Trng hp 2: Khi ion kim loi ngtrcAl H2O u tin b kh trc.

2H2O + 2e H2 + 2OH-

cc anot (+)

+ Xy ra qu trnh oxi ha

Trng hp 1: Khi ion gc axit khngcha oxi (Cl-, Br-) ion (Cl-, Br-) u tinb oxi ha trc.

2Cl- + 2e Cl2

Trng hp 2: Khi ion gc axit c chaoxi (SO42-, NO3-) H2O u tin b oxi hatrc.

2H2O O2 + 4H+ + 4e


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Th d 1:

in phn dung dch CuCl2;CuCl2 Cu2+ + 2Cl-


+ Xy ra s khion Cu2+ + Xy ra s oxi ha ion O2-

Cu2+ + 2e Cu 2Cl-Cl2 + 2e

+ Phng trnh in phn: CuCl2pdd

Cu + Cl2 (H2O khngtham gia in phn) Ta iu ch c kim loi Cu

Th d 2: in phn dung dch AgNO3; AgNO3 Ag+ + NO3-


+ Xy ra s khion Ag+ + Xy ra s oxi ha phn t H2O

Ag+ + 1e Ag 2H2O O2 + 4H+ + 4e

H2O tham gia qu trnh in phn.

+ Phng trnh in phn: 2AgNO3 + H2Opdd

2Ag + 2HNO3 + 1/2O2 Ta iu ch c kim loi Ag

Th d 3: in phn dung dch NaCl (c mng ngn xp); NaCl Na+ + Cl-


+ Xy ra s kh phn t H2O + Xy ra s oxi ha ion Cl-

2H2O + 2e H2 + 2OH- 2Cl- Cl2 + 2e

H2O tham gia qu trnh in phn.

+ Phng trnh in phn: 2NaCl + 2H2Opdd

2NaOH + Cl2 + H2 Ta khngiu ch c kim loi Na

III- TNH LNG CHT THU C CC IN CC (NH LUT FARAAY)

Cng thc:

. .

.

A I tm

n F=

Th d: Tnh khi lng Cu thu c cc catot sau 1 gi in phn dung dch CuCl2 vicng dng in l 5A.

Phng trnh in phn: CuCl2 pdd Cu + Cl2


m : khi lng cht thu c in cc (g)I : cng dng in (A)t : thi gian in phn (s)n : s electron cho hoc nhnF : 96.500 (hng s Faraay)


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Khi lng Cu thu c l64.5.3600

5,932.96500

Cum gam= =

CHNG 6: KIM LOI KIM KIM LOI KIM TH - NHM

A. KIM LOI KIM HP CHT CA KIM LOI KIM

I- V TR TNH CHT KIM LOI KIM

IALiNa

KRbCs

II- TNH CHT HA HC

+Do cc kim loi kim c nng lng ion ha nh cc kim loi kim c tnh kh

mnh. +M M +1e

IALiNaK

RbCs

1. Tc dng vi phi kim

a) Vi oxi (O2)


1. V tr v cu hnh

+ Cc kim loi kim u thuc nhm IA trong bng HTTH chng u c 1e lp ngoi cng.

+ Cu hnh electron lp ngoi cng c c dng: ns

1

kim loi kim uthuc nguyn t s.

2. Tnh cht

+ Cc kim loi kim c mu trng bc v c nh kim, dn in tt.

+ Cc kim loi kim u c kiu mng lp phng tm khi(km c khch) kim loi kim c tonc v tos v cng thp.

+ Khi i t trn xung di (Li Cs) th:

Tnh kh tng dn

Nng lng ion ha gim dn tonc , tos gim dn

m in gim dn

Ch : Tnh cht ha hc v tnh cht vt l cc kim loi kim bin i theo mtqui lut l do cc kim loi kim c cng mt kiu mng lp phng tm khi.

+ Trong t nhin, cc kim loi kim u nm dng hp cht v u

c s oxi ha l +1.


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vi dung dch mui

vi CO2


0 +1

22

4Na +O 2Na O (trong khng kh kh)

0 +1

22 2

Na +O 2Na O2 (trong kh oxi kh)

b) Vi clo (Cl2)

0 +1

22Na +Cl 2Na Cl

2. Tc dng vi axit

+ Tt c kim loi kim u n khi tc dng vi axit v d dng kh ion H+thnh kh H2.

0 +1

22K + 2HCl 2K OH + H

3. Tc dng vi nc

+Kim loi kim kh nc d dng v phn ng mnh lit t (Li Cs). Do bo qun kim loi kim, ngi ta ngm chng trong du ha.

0 +1

222K + 2H O 2K OH + H

III- IU CH KIM LOI KIM

+ Dng phng php in phn nng chyhp cht mui clorua ca chng.

NaCl pnc Na + 1/2Cl2

IV- NG DNG

+ Hp kim (Na K) dng lm cht trao i nhit trong l phn ng ht nhn.

+ Hp kim (Li Al) siu nh, c dng trong k thut hng khng.

+ Xesi (Cs) c dng lm t bo quang in.

B. HP CHT CA KIM LOI KIM (NaOH NaHCO3 Na2CO3)

I- NaOH (natri hiroxit) xt n da

1. Tnh cht vt l

+ NaOH l cht rn khng mu, d nng chy, ht m mnh v tan tt trongnc.

2. Tnh cht ha hc

+ Dung dch NaOH th hin l mt baz mnh.

+ lm qu tm ha xanh+ tc dng vi dung dch mui

NaOH + + kh CO2+ tc dng vi axit

Th d :

2NaOH + CuCl2 Cu(OH)2 + 2NaCl

3NaOH + FeCl3 Fe(OH)3 + 3NaCl

NaOH + CO2 NaHCO3


NaOH

CO

n

n

NaHCO3 1 2 Na2CO3NaHCO3Na2CO3


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vi axit

nhit phn

lng tnh


2NaOH + CO2 Na2CO3 + H2O

NaOH + HCl NaCl + H2O

3. iu ch - ng dng

a) iu ch:

+ Trong cng nghip, NaOH c iu ch bng cch in phn dungdch

mui n bo ha (c mng ngn xp).pdd

2 2 2mnx2NaCl + 2H O 2NaOH + Cl + H

b) ng dng:

+ NaOH c dng trong vic ch bin x phng, ch phm nhum,tinh ch qung nhm,

I- NaHCO3 (natri hirocacbonat)1. Tnh cht vt l

+ NaHCO3 l cht rn mu trng t tan trong nc.

2. Tnh cht ha hc

+ NaHCO3 l hp cht lng tnh v d nhit phn.

NaHCO3 + HCl NaCl + CO2 + H2O

NaHCO3 + NaOH Na2CO3 + H2O

NaHCO3o

t Na2CO3 + CO2 + H2O

3. iu ch - ng dng

a) iu ch:

NaOH + CO2 NaHCO3b) ng dng:

+ NaHCO3 dng lm thuc au d dy v lm bt n.

II- Na2CO3 (natri hirocacbonat)

1. Tnh cht vt l

+ Na2CO3 l cht rn mu trng, tan nhiu trong nc. nhit thng tnti dng ngm nc Na2CO3.10H2O.

2. Tnh cht ha hc+ Dung dch Na2CO3 c tnh kim (th hin tnh baz).

+ lm qu tm ha xanhNaOH + + tc dng vi axit

+ tc dng vi dung dch mui

Th d :Na2CO3 + 2HCl 2NaCl + CO2 + H2O

Na2CO3 + CaCl2 CaCO3 + 2NaCl



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3. iu ch - ng dng

a) iu ch:

2NaOH + CO2 Na2CO3 + H2O

b) ng dng:

+ Na2CO3 dng trong cng nghip thy tinh, bt git, phm nhum, giy, si,..

I- KNO3 (kali nitrat)

1. Tnh cht

+ KNO3 l tinh th khng mu, bn trong khng kh v tan tt trong nc.

+ nhit > 333oC, KNO3 b phn hy:

KNO3o

t KNO2 + 1/2O2

2. ng dng

+ KNO3 dng lm phn bn ha hc (phn m, phn kali), ngoi ra cn

dng iu ch thuc n.2KNO3 + 3C + S

ot N2 + 3CO2 + K2S

BI S 7: KIM LOI KIM TH - HP CHT QUAN TRNG KIM LOI KIM TH -NC CNG

A. KIM LOI KIM TH

I- V TR CU HNH ELECTRON

2. Tnh cht

+ Cc kim loi kim th c mu trng bc v c th dt mng, tonc, tos v cng thp nhng vn cao hn kim loi kim. Do c nhiu kiu mng khc nhau kim loi kimth c tonc, tos, D bin i khng theo mt qui lut nht nh nh kim loi kim.

II- TNH CHT HA HC

+ Kim loi kim th c nng lng ion ha nh nhng vn ln hn nhm IA Kimloi kim th c tnh kh mnh (nhng yu hn nhm IA) v cng tng dn t Be Ba.

+ Trong cc hp cht, kim loi kim th c s oxi ha l +2.

2+M M +2e

IIA


1. V tr v cu hnh

+ Cc kim loi kim th u thuc nhmIIA trong bng HTTH chng u c 2e lpngoi cng.

+ Cu hnh electron lp ngoi cng cc dng: ns2 kim loi kim u thuc nguyn ts.

+ Cc kim loi kim c nhiu kiu mngkhc nhau.

IIA

BeMgCaSrBa

tinh th lc phng

tinh th lc phng lp phng tm din

lp phng tm din

lp phng tm khi

+ Khi i t trn xung di (Be Ba) th: Tnh kh tng dn

- phi kimTc dng: - axit

- nc


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+ Vi dung dch mui

+ Vi CO2:


BeMgCaSrBa

1. Tc dng vi phi kim

Th d:

0 +2

2

0 +2

2 2

2 Mg + O 2 Mg O

Ca + Cl Ca Cl

2. Tc dng vi axit (HCl, H2SO4, HNO3)Th d:

0 +2

2 2

0 +2

2 4(long) 4 2

0 +6 +2 -2

22 4(c) 4 2

0 +5 +2 -3

3(long) 3 2 4 3 2

Mg + HCl Mg Cl + H

Mg + H SO MgSO + H

4Mg + 5H S O 4MgSO + H S + 4H O

4Mg + 10H N O 4Mg (NO ) + N H NO + 3H O

3. Tc dng vi nc

+ nhit thng, ch c Be khngtc dng vi nc.0 +2

2

0 +2

2

2 2

2 2

Ca + 2H O Ca OH) + H

Ba + 2H O Ba OH) + H

(

(

Ch : Ring Mg tc dng vi nc ch to MgO v kh hiro

III- IU CH KIM LOI KIM TH

+ Dng phng php in phn nng chyhp cht mui clorua ca chng.

CaCl2 pnc Ca + Cl2

MgCl2 pnc Mg + Cl2

B. HP CHT CA KIM LOI KIM TH (Ca(OH)2 CaCO3 CaSO4)

I- Ca(OH)2 canxi hiroxit vi ti1. Tnh cht vt l

+ Ca(OH)2 l cht rn mu trng, t tan trong nc, dung dch Ca(OH)2 gi lnc vi trong.

2. Tnh cht ha hc+ lm qu tm ha xanh+ tc dng vi dung dch mui

Ca(OH)2 + + kh CO2+ tc dng vi axit

Th d: : : Ca(OH)2 + Na2CO3 CaCO3 + 2NaOH

+ Khi dn kh CO2 t t vo nc vi trong th:



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+ Vi axit:


lc u : Ca(OH)2 + CO2 CaCO3 + H2O

sau : CaCO3 + CO2 + H2O Ca(HCO3)2 (tan)

hin tng: xut hin kt ta trng, sau kt ta tan.

Ch : nu nc vi trong d, th ch to thnh kt ta.

Ca(OH)2 + 2HCl CaCl2 + 2H2O

3. iu ch v ng dng

a) iu ch:

CaO + H2O Ca(OH)2(vi sng) (vi ti)

hay: Ca + 2H2O Ca(OH)2 + H2

b) ng dng:+ Ca(OH)2 c dng trong vic sn xut amoniac (NH3), clorua vi

(CaOCl2) v trong vt liu xy dng,..

II- CaCO3 canxi cacbonat vi

1. Tnh cht vt l+ CaCO3 l cht rn mu trng, khng tan trong nc.

2. Tnh cht ha hc

a) nhit phnCaCO3

ot CaO + CO2

b) tc dng vi axit

CaCO3 + 2HCl CaCl2 + CO2 + H2O

CaCO3 + 2CH3COOH (CH3COO)2Ca + CO2 + H2O

c) CaCO3 tan dn trong nc c ha tan CO2

CaCO3 + CO2 + H2O Ca(HCO3)2 (tan)

(hin tng xm thc vi)Nu :

Ca(HCO3)2

ot CaCO3 + CO2 + H2O

(hin tng to thnh thch nh trong hang ng)

3. iu ch - ng dng - trng thi t nhin

a) iu ch: ta c cc phn ng sau :

Ca(OH)2 + CO2 CaCO3 + H2O

Ca(OH)2 + CO2 CaCO3 + H2O

CaO + CO2 CaCO3

Na2CO3 + CaCl2 CaCO3 + 2NaCl



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b) ng dng:

+ CaCO3 dng lm vt liu xy dng, sn xut vi, xi mng, thytinh, hoa (tc tng), phn (thuc nh rng),

c) Trng thi t nhin

+ Trong t nhin CaCO3 tn ti di dng hoa, phn v lthnh phn chnh ca v v mai cc loi c.

III- CaSO4 canxi sufat (thch cao)

CaSO4.2H2O 160o

C CaSO4.H2Oo

t C CaSO4 (thch cao sng) (thch cao nung) (thch cao khan)

+ Thch cao nung dng nn tng, b bt khi gy xng, c khun,

+ Thch cao sng c dng sn xut xi mng.

C. NC CNG

I- KHI NIM PHN LOI

1. Khi nim+ Nc cng l nc c cha nhiu ion Ca2+ v Mg2+, nc khng cha

hoc cha rt tion Ca2+ v Mg2+ th gi l nc mm.Th d : Cc ngun nc t nhin (sng, ao, h, sui, nc ngm,..) l nc cng.

2. Phn loi

nc cng cha cc ion Th dtm thi Ca2+, Mg2+, HCO3- Ca(HCO3)2, Mg(HCO3)2,

vnh cu Ca2+, Mg2+, ion Cl- hoc SO42-CaSO4, CaCl2, MgCl2,

MgSO4ton phn tt c cc ion trn tt c cc cht trn

Ch : Cc ngun nc t nhin thng l nc cng ton phn.

II- TC HI CA NC CNG CC BIN PHP LM MM NC CNG

1. Tc hi ca nc cng

+ Git bng x phng (C17H35COONa) trong nc cng s lm hao tn xphng, khng sch v lm cho qun o mau mc nt.

+ Nu dng nc cng nu n th lm cho thc phm lu chn v lm gim

mi v.+ Khi un nc cng trong cc ni hi lu ngy s to mt lp cn bm vo

gy lng ph nhin liu v khng an ton.

2. Cc bin php lm mm nc cng

* Nguyn tc chung lm mm nc cng:

+ Lm gim nng cc ion Ca2+ v Mg2+ trong nc cng.

- phng php kt ta* C 2 phng php lm mm nc cng

- phng php trao i ion

a) phng php kt ta

+ Chuyn cc ion Ca2+ v Mg2+ thnh hp cht khng tan (kt ta)



16/28


v loi khi dung dch.

Nc cng Cch lm mm Phng trnh

Tm thi(Ca2+, Mg2+, HCO3-)

Cch 1: un si nc cng

Ca(HCO3)2

ot CaCO3 + CO2 + H2O

Mg(HCO3)2

ot MgCO3 + CO2 + H2O

Cch 2: dng ha cht sau:Na2CO3, Na3PO4, NaOH,KOH, Ca(OH)2 (va )

Ca(HCO3)2 + Na2CO3 CaCO3 + 2NaHCO3

3Ca(HCO3)2 + 2Na3PO4 Ca3(PO4)2 + 6NaHCO3

Ca(HCO3)2 + Ca(OH)2 (va ) 2CaCO3 + 2H2O

Vnh cu

Ca2+, Mg2+, SO42-

hoc Cl-)

Cch 2: Ch dng ha chtsau: Na2CO3, Na3PO4

b) phng php trao i ion+ Dng nhng vt liu v c hoc hu c c kh nng trao i mts ion (vt liu cationit, vt liu zeolit). Cc ion Ca2+ v Mg2+ i vo l trng polime thch cho cc ion Na+ hoc H+ i ra vo dung dch.

Bi tp:

BI S 8: NHM - HP CHT QUAN TRNG CA NHM

I- V TR CA NHM - CU HNH ELECTRON TNH CHT VT L

1. V tr - cu hnh electron

Al (Z = 13): 1s2 2s2 2p6 3s2 3p1 hay: [Ne] 3s2 3p1

Al thuc s 13, chu k 3 nhm IIIA, nhm l nguyn t p.

Trong hp cht nhm u c s oxi ha l +3.

2. Tnh cht vt l+ Nhm l kim loi c mu trng bc, tonc = 660oC, thuc kim loi nh, kh

mm, d dt mng v ko si.



17/28


II- TNH CHT HA HC

+ Nhm l kim loi c tnh kh mnh (ch km kim loi mho1m IA v IIA).

3+

Al Al + 3e

- phi kim (O2, Cl2)

-dung dch axit (HCl, H2SO4, HNO3)Al phn ng vi - oxit kim loi (phn ng nhit nhm)- nc- dung dch kim (NaOH, KOH, Ba(OH)2)

1. Phn ng vi phi kim (O2, Cl2)o

0 +3t

22 3

0 +3

2 3

4Al + 3O 2 Al O

2Al + 3Cl 2AlCl

Ch : Nhm bn trong khng kh nhit thng l do c mng mng Al2O3 bo v.

2. Tc dng vi axit0 +3

3 2

0 +3

22 4(long) 4 3 2

0 +6 +3 +4

22 4(c) 4 3 2 2

0 +5 +3 +4

3(c) 3 3 2 2

0 +5 +3

3(long) 3

2Al +6HCl 2AlCl +3H -

2Al + 3H SO Al (SO ) + 3H

2Al + 6H S O Al (SO ) + 3S O + 6H O

Al + 6H N O Al(NO ) + 3NO + 3H O

Al + 4H N O Al(NO

+2

3 2

0 +5 +3 +1

23(long) 3 3 2

) + N O + 2H O

8Al + 30H N O 8Al(NO ) + 3N O + 15H O

Ch :(Al, Fe, Cr) khngphn ng (th ng) vi H2SO4 v HNO3 m c, ngui

3. Tc dng vi oxit kim loi (phn ng nhit nhm)

+ y chng qua l phn ng nhit luyn vi cht kh l Al (kh oxit kim loit Zn tr i).

Th d: 2Al + Fe2O3o

tAl2O3 + 2Fe

8Al + 3Fe3O4o

t 4Al2O3 + 9Fe

2Al + 3CuO otAl2O3 + 3Cu

4. Tc dng vi H2O


(nhm t bc chy khi tip xc vi kh Cl2)

Al + oxit kim loio

tAl2O3 + kim loi


18/28

(cht kh) (cht oxi ha)

lc

lc


+ Thc t, nhm khngtc dng vi nc d nhit no v c mngmng Al2O3 bo v.

+ Nu ph b lp Al2O3 (nhm nguyn cht) th Al s tc dng vi ncnhng phn ng ny mau chng dng li v to lp Al(OH)3 khng tan trong nc bm trn bmt nhm khng cho nhm tip xc vi nc

0 +3

2 3 22Al + 6H O 2Al(OH) + 3H

5. Tc dng vi dung dch kim

+ Nhng vt bng nhm s b tan trong dung dch kim (NaOH, KOH,Ba(OH)2).

Nguyn nhn: Al2O3 v Al(OH)3 l hp cht lng tnh c th tan trong dung dch axit v kim,nn khi cho Al ( b ph bi mng Al2O3) vo dung dch kim thi:

Lp Al2O3 lng tnh nn tan trc

Al2O3 + 2NaOH 2NaAlO2 + H2O (1)

K tip Al kh nc

0 +3

2 3 22 Al + 6H O 2 Al(OH) + 3H

(2)

Lp Al(OH)3 lng tnh nn tip tc tan trong NaOH

Al(OH)3 + NaOHNaAlO2 + 2H2O (3)(natri aluminat) - tan

Cc phn ng (2), (3) lun phin phn ng cho n khi Al b ha tan ht.

+ Nh vy khi cho Al vo dung dch NaOH, phng trnh ha hc c th vit gn l0 +3

2 2 2

3Al + NaOH + H O Na AlO + H

2

III- IU CH NHM - NG DNG CA NHM

1. iu ch nhm

+ Dng phng php in phn Al2O3 nng chy.Nguyn liu: i t qung boxit (Al2O3.2H2O c ln Fe2O3 v SiO2)

Bc 1: lm sch qung boxit bng s sau:

Bc 2: in phn nng chy Al2O3. Trong qu trnh in phn, ngi ta phi thmcht criolit (Na3AlF6) vo vi 3 mc ch:

+ H nhit nng chy ca Al2O3 (t 2050oC 900oC) tit kim nhinliu.

+ Tng tnh dn in ca hn hp cht lng.

+ To hn hp c khi lng ring nh hn nhm nn ni trn b mt nhm,ngn khng cho nhm b oxi ha trong khng kh.

in phn nng chy Al2O3; Al2O3 2Al3+ + 3O2-



19/28

(catot) (anot)


+ S in phn:cc catot (-) cc anot (+) lm bng than ch (C)

+ Xy ra s khion Al3+ + Xy ra s oxi ha ion O2-

Al3+ + 3e 2Al 2O2-O2 + 4e

+ Phng trnh in phn: Al2O3 pnc 2Al + 3/2O2

Sau mt thi gian in phn, ngi ta phi thay than ch cc dng v kh oxi sinh ra tchy C.

2. ng dng ca nhm

+ Nhm dng lm vt liu ch to my bay, t, tn la, trang tr nt tht,

+ Hn hp tecmic (Al + Fe2O3), c dng hn cc ng ray.

B - HP CHT QUAN TRNG CA NHM

I- Al2O3 nhm oxit

1. Tnh cht vt l+ Al2O3 l cht rn mu trng, khng tan trong nc, tonc = 2050oC.

2. Tnh cht ha hc

+Al2O3 l hp cht lng tnh, tan c trong dung dch axit v kim.

Al2O3 + 6HCl 2AlCl3 + 3H2O

Al2O3 + 2NaOH 2NaAlO2 + H2O (natri aluminat)

3. iu ch

2Al(OH)3 otAl2O3 + 3H2O

4. ng dng

+ Al2O3.2H2O l thnh phn chnh ca qung boxit dng sn xut nhm.

+ Al2O3 dng lm qu corion (ch to mi, giy nhm,), saphia,cht xc tc,..

II- Al(OH)3 NHM HIROXIT

1. Tnh cht vt l

+ Al(OH)3 l cht rn mu trng, khng tan trong nc l cht kt ta dangkeo.

2. Tnh cht ha hc

+ Al(OH)3 l mt hiroxit lng tnh, , tan c trong dung dch axit v kim(trong tnh baz tri hn tnh axit).

Al(OH)3 + 3HClAlCl3 + 3H2O

Al(OH)3 + NaOH NaAlO2 + 2H2O (natri aluminat)

Ngoi ra: Al(OH)3 l cht km bn vi nhit:

2Al(OH)3 otAl2O3 + 3H2O

3. iu ch

Cch 1: Thi kh NH3 vo dung dch mui Al3+.


NaAlO2 c th vit l Na[Al(OH)4]


20/28


AlCl3 + 3NH3 + 3H2OAl(OH)3 + 3NH4NO3(kt ta keo trng)

Hin tng: Thi kh NH3 d vo dung dch mui nhm xut hin kt ta keo trng.

Cch 2: Cho dung dch kim tc dng vi dung dch mui nhm.

III- MUI NHM

+ Mi nhm c ng dng quan trng nht l phn chua c kh nng lm trong nc. Cng thc phn chua: K2SO4.Al2(SO4)3.24H2O hay vit tc: KAl(SO4)2.12H2O

Ch : Na2SO4.Al2(SO4)3.24H2O hi lphn nhm

Bi tp:

CHNG 7: ST V MT S HP CHT QUAN TRNG CA ST

BI S 9 : ST

I- V TR CU HNH ELECTRON TNH CHT VT L

1. V tr v cu hnh

Fe (Z = 26): 1s2

2s2

2p6

3s2

3p6

3d6

4s2

hay vit tc: [Ar] 3d6

4s2

St thuc s 26, chu k 4 nhm VIIIB Fe l nguyn t d. Trong cc hp cht Fe c s oxiha l +2 v +3.

2. Tnh cht


+ Trng hp 1: Nh dung dch NaOH d vodung dch Al2(SO4)3

(dd NaOH)

(dd Al2(SO4)3)

hin tng: lc u xut hin kt ta keo trng,sau kt ta tan.

Phng trnh:Al2(SO4)3 + 6NaOH 2Al(OH)3 + 3Na2SO4

Al(OH)3 + NaOH NaAlO2 + 2H2O

+ Trng hp 2: Nh dung dch Al(NO3)3 d vodung dch NaOH

(dd Al(NO3)3)

(dd NaOH)

hin tng: kt ta keo trng va xut hin ribin mt..

Phng trnh:Al(NO3)3 + 3NaOH Al(OH)3 + 3NaNO3

Al(OH)3 + NaOH NaAlO2 + 2H2O


21/28


+ St l kim loi c mu trng hi xm, thuc kim loi nng(D = 7,9 g/cm3),tonc = 1540oC. St c tnh dn in v dn nhit tt, c bit c tnh nhim t.

+ Ty theo nhit , st c kiu mng tinh th lp phng tm din hoc lpphng tm khi.

II- TNH CHT HA HC

+ St c tnh kh trung bnh. Trong phn ng ha hc, st c th tng s oxi ha ln

mc +2 hoc +3.

(tnh kh)

- phi kim (O2, Cl2, S)

Fe phn ng vi - dung dch mui

-dung dch axit (HCl, H2SO4, HNO3)

1. Phn ng vi phi kim (O2, Cl2, S)o

o

o

0 +8/3t

32 4

0 +3t

2 3

0 +2t

3Fe + 2O Fe O

2Fe + 3Cl 2FeCl

Fe + S Fe S

2. Tc dng vi axit

0 +2

2 2

0 +2

2 4(long) 4 2

0 +6 +3 +4

22 4(c) 4 3 2 2

0 +5 +3 +4

3(c) 3 3 2 2

0 +5 +3

3(long) 3 3

Fe + 2HCl FeCl + 3H

Fe + H SO FeSO + H

2Fe + 6H S O Fe (SO ) + 3S O + 6H O

Fe + 6H N O Fe(NO ) + 3N O + 3H O

Fe + 4H N O Fe(NO ) +

+2

2N O + 2H O

Ch : (Al, Fe, Cr) khngphn ng (th ng) vi H2SO4 v HNO3 m c, ngui

3. Tc dng vi dung dch muiTh d 1:0 +2

4 4

0 +3 +2

3 3 3 2

Fe + CuSO FeSO + Cu

Fe + 2Fe(NO ) 3Fe(NO )

Th d 2:0 + +2 0

3 3 2Fe + 2Ag NO Fe(NO ) + 2 Ag

Nu dung dch AgNO3 d th:+2 + +3 0

3 2 3 3 3Fe(NO ) + Ag NO Fe(NO ) + 2Ag

III- TRNG THI T NHIN

+ Trong t nhin, st ch yu tn ti dng hp cht, thng tn ti trong cc qung:

Qung henatit : c 2 dng:



22/28


+ Hematit (ch cha Fe2O3)

+ Hematit nu (cha Fe2O3.nH2O)

Qung manhentit : Fe3O4 (c hm lng st cao nht, him c trong tnhin).

Qung xierit : FeCO3

Qung pyrit st : FeS2

BI S 10 : MT S HP CHT QUAN TRNG CA ST

- St c 2 loi hp cht quan trng l: hp cht st (II) v hp cht st (III).

I - HP CHT ST (II) Fe2+

(tnh oxi ha) (tnh kh)

1. St (II) oxit - FeO

a) Tnh cht vt l

+ FeO l cht rn mu en, khng tan trong nc, khng c trong

t nhin. b) Tnh cht ha hc

+ FeO d b oxi ha thnh hp cht Fe3+.Th d:

+2 +5 +3 +4

3(long) 3 3 2

0 +5 +3 +4

3(c) 3 3 2 2

3FeO + 10H N O 3Fe(NO ) + 3N O + 5H O

FeO + 4H NO Fe(NO ) + N O + 2H O

Ngoi ra :0 +3

22 32FeO + 1/2O Fe Oot

c) iu chFeCl2 + 2NaOH Fe(OH)2 + 2NaCl

(xanh nht)

Fe(OH)2o

t FeO + H2O

2. St (II) hiroxit Fe(OH)2

a) Tnh cht vt l

+ Fe(OH)2 l cht rn c mu xanh nht, khng tan trong nc.

b) Tnh cht ha hc

+ Fe(OH)2 cng d b oxi ha thnh hp cht Fe3+.Th d: Khi nung Fe(OH)2 trong khng kh n khi lng khng i th thu c cht rn saucng mu nu .


nhng tnh cht ha hc c trngca hp cht st (II) l tnh kh.


23/28


o

o

+2 +3t

2 2 2 3

+3 +3t

23 3 2

4Fe(OH) + O + 2H O 4Fe(OH)

2Fe(OH) Fe O + 3H O

3. Mui Fe2+

+ Mui cng d b oxi ha thnh hp cht Fe3+.

Th d: Dung dch FeSO4 lm mt mu tm ca dung dch KMnO4.

10FeSO4 + 2KMnO4 + 8H2O 5Fe2(SO4)3 + K2SO4 + 2MnSO4 + 8H2ONgoi ra: 2FeCl2 + Cl2 2FeCl3

II - HP CHT ST (III) Fe3+

(tnh oxi ha)

1. St (III) oxit Fe2O3

a) Tnh cht vt l

+ Fe2O3 l cht rn mu nu, khng tan trong nc.

b) Tnh cht ha hc

+ Fe2O3 l mt oxit baz.Th d:

+3 +3

2 3 3 2

+3 +3

2 23 2 4 4 3 2

+3 +3

2 3 3 3 3 2

Fe O + 6HCl FeCl + 3H O

Fe O + 3H SO Fe (SO ) + 3H O

Fe O + 6HNO 2Fe(NO ) + 3H O

c) iu cho

+3 +3t

23 3 22Fe(OH) Fe O + 3H O

2. St (III) hiroxit Fe(OH)3

a) Tnh cht vt l

+ Fe(OH)3 l cht rn c mu nu , khng tan trong nc.

b) Tnh cht ha hc

+ Fe(OH)3 d tan trong dung dch axit.o

o

o

+3 +3t

3 3 2

+3 +3t

23 2 4 4 3 2

+3 +3

t3 3 3 3 2

4Fe(OH) + 3HCl FeCl + 3H O

2Fe(OH) + 3H SO Fe (SO ) + 6H O

Fe(OH) + 3HNO Fe(NO ) + 3H O

Ngoi ra: d b nhit phn:

o+3 +3

t23 3 22Fe(OH) Fe O + 3H O


Tnh cht ha hc ca hpcht st (III) l tnh oxi ha.


24/28


c) iu ch

FeCl3 + 3NaOH Fe(OH)3 + 3NaCl

Hay: o+2 +3

t

2 2 2 34Fe(OH) + O + 2H O 4Fe(OH) (xanh nht) (nu )

3. Mui Fe3+

a) Tnh cht vt l+ a s cc dung dch mui Fe3+ u c mu vng, tan trong nc.

b) Tnh cht ha hc

+ Cc mui Fe3+ c tnh oxi ha, d b khthnh mui Fe2+.

Th d:

o

o

+3 +2t

3 2

+3 +2t

3 2 2

2FeCl + Fe 3FeCl

2FeCl + Cu 2FeCl + CuCl

III- NHN BIT ION Fe2+ v ion Fe3+

Cch 1: Dng dung dch kim (NaOH, KOH)

+ i vi ion Fe2+:

FeCl2 + 2NaOH Fe(OH)2 + 2NaCl(xanh nht)

Fe(OH)2 lu trong khng kh b ha nu :o

+2 +3t

2 2 2 34Fe(OH) + O + 2H O 4Fe(OH)

+ i vi ion Fe3+:

FeCl3 + 3NaOH Fe(OH)3 + 3NaCl(nu )

Cch 2: Dng kh NH3 thi vo dung dch Fe2+ hoc Fe3+.

FeCl3 + 3NH3 + 3H2O Fe(OH)3 + 3NH4NO3(nu )

FeCl2 + 2NH3 + 2H2O Fe(OH)2 + 2NH4NO3(xanh nht)

IV- NG DNG

+ FeCl3 c dng lm cht xc tc trong tng hp cht hu c.+ Fe2O3 dng pha sn chng g.

BI S 11 : HP KIM CA ST (GANG THP)

- St tinh khit t c x dng trong thc t, nhng hi kim ca st nh gang, thp thc x dng rt ph bin.

I- GANG

1- Khi nim phn loi

+ Gang l hp kim ca st vi cacbon (Fe C), trong cacbon chim (2% 5%) khi lng, ngoi ra cn c cha mt lng nh mt s nguyn t khc nh: Si, Mn, S,

+ C 2 loi gang: gang trng v gang xm



25/28


Gang trng: l gang c cha t cacbon v rt t silic (Si) nhngcha nhiu xementit (Fe3C). Gang trng rt cng v gin c dng luyn thp.

Gang xm: l gang c cha nhiu cacbon v silic. Gang xm kmcng v km gin hn gang trng. Gam xm c dng c cc b phn ca my, ng dnnc,..

2- Sn xut gang.

a) Nguyn tc sn xut gang:+ Kh qung st oxit bng than cc trong l cao.

b) Nguyn liu:

+ Qung hematit Fe2O3), than cc (C) v cht chy (CaCO3 hocSiO2).

c) Cc phn ng xy ra trong qu trnh luyn gang

Phn ng to cht kh CO (CO c to thnh trong phn phu l)

Phn ng kh Fe2O3 to thnh Fe (Fe c to ra trong phn thn l) Phn ng to x (CaSiO3) (x l c to ra trong phn bng l)

d) S to thnh gang

+ phn bng l nhit khong 1500oC, st nng chy c hatan mt phn cacbon v mt lng nh cc nguyn t Si, Mn,.. to thnh gang.

II- THP - SN XUT THP

1. Khi nim

+ Thp l p kim ca st v cacbon, trong cacbon chim (0,01% 2%)

khi lng, ngoi ra cn c cha mt s nguyn t khc nh: Si, S, Mn, Cr, Ni,2. Sn xut thp

+ Nguyn tc chung sn xut thp l lm gim hm lng cc tp cht (C, S,Si, Mn,..) c trong gang bng cch oxi ha cc tp cht thnh oxit ri bin thnh x v tch rakhi thp.

Bi tp:

BI S 12 : CROM V HP CHT CA CROM



26/28


A- CROM

I- V TR CU HNH ELECTRON

1. V tr v cu hnh

Cr (Z = 24): 1s2 2s2 2p6 3s2 3p6 3d5 4s1 hay vit tc: [Ar] 3d5 4s1

Crom thuc s 24, chu k 4 nhm VIB Cr l nguyn t d

. Trong cc hp cht Cr c s oxiha ph bin l +2, +3 v +6.

2. Tnh cht

+ Crom l kim loi c mu trng bc, thuc kim loi nng(D = 7,2 g/cm3), Crl kim loi cng nht nn dng n ct thy tinh.

+ Crom c kiu mng tinh th lp phng tm khi.

+ Trong t nhin crom ch c dng hp cht, ph bin nht l qung cromit(FeO.Cr2O3 c ln Al2O3 v SiO2).

II- TNH CHT HA HC

Zn Cr Fe

1. Tc dng vi phi kimTh d:

o

o

o

0 +3t

22 3

0 +3t

2 3

0 +3t

2 3

4Cr + 3O 2Cr O

2Cr + 3Cl 2Cr Cl

2Cr + 3S Cr S

Ch : Crom cng c mng oxit Cr2O3 bo v bn ngoi (ging Al), nn crom khng tc dngvi nc.

2. Tc dng vi axit

+ nhit thng, crom khngphn ng vi axit HCl v H2SO4 long. Khiun nnglp Cr2O3 tan ra nn crom s kh H+ ca axit gii phng kh H2.

o

o

0 +2

t 2 2

0 +2t

2 4 4 2

Cr + 2HCl Cr Cl + H

Cr + H SO CrSO + H

Ch : (Al, Fe, Cr) khngphn ng (th ng) vi H2SO4 v HNO3 m c, ngui

III- IU CH CROM - NG DNG CROM

1. iu ch crom

+ Cr2O3 c tch ra t qung cromit. Sau dng phng php nhitnhm (thuc phng php nhit luyn) ta thu c crom.

2Al + Cr2O3o

t

Al2O3 + 2Cr

2. ng dng

+ Trong cng nghip crom dng sn xut thp (thp khng g), crom dng m ln cc vt chng n mn, cng v p,


+ Cr c tnh kh mnh hn Fe nhng yu hon Zn. Tnh cht ha hc ca crom l tnh kh+ Trong cc hp cht Cr c s oxi ha ph bin l +2,+3 v +6.

(tnh kh)

phn ngging Al


27/28


B- HP CHT QUAN TRNG CA CROM

I- HP CHT CROM (II) Cr2+

- Tnh cht ha hc c trng ca hp cht Cr (II) l tnh kh.

1-+2

Cr O - crom (II) oxit

- CrO l mt oxit baz v c tnh kh.

2-+2

2Cr(OH) - crom (II) hidroxit

+ Cr(OH)2 l cht rn mu vng khng tan trong nc

+ Cr(OH)2 th hin l mt baz v c tnh kh.o

+2 +3t

2 2 2 34Cr (OH) + O + 2H O 4Cr (OH)

(mu vng) (lc xm)

3. Mui crom (II)

+ Mui Cr (II) th hin tnh kh mnh.+2 +3

2 2 32Cr Cl + Cl 2Cr Cl

II- HP CHT CROM (III) Cr3+

1-+3

2 3Cr O - crom (III) oxit

+ Cr2O3 l cht rm mu lc thm khng tan trong nc.+ Cr2O3 l mt oxit lng tnh (ging Al2O3).

Th d:

Cr2O3 + 6HCl 2CrCl3 + 3H2O

Cr2O3 + 2NaOH 2NaCrO2 + H2O

2-+3

3Cr (OH) - crom (III) hidroxit

+ Cr(OH)3 l cht rn mu lc xm, khng tan trong nc.

+ CrOH)3 l mt hiroxit lng tnh (ging Al(OH)3).Th d:

Cr(OH)3 + 3HCl CrCl3 + 3H2O

Cr(OH)3 + NaOH NaCrO2 + 2H2O

3. Mui crom (III)- Cr3+

(tnh oxi ha) (tnh kh)

III- HP CHT CROM (VI) Cr6+


+ Mui Cr (III) va th hin tnh kh, va th hin tnhoxi ha.+ Mui Cr3+ quan trng nht l phn crom kali:

K2SO4.Cr2(SO4)3.24H2O dng lm cht thuc da, chtcm mu trong ngnh nhum vi.+ -

+2 +3 +6H OH

Cr Cr Cr


28/28

(axit icromic)


1-+6

3CrO - crom (VI) oxit

+ CrO3 l cht rn mu thm.

+ CrO3 c tnh oxi ha rt mnh c th tc dng vi (S, C, NH3, C2H5OH,..)

+ CrO3 th hin l mt oxit axit, tc dng vi nc to thnh axit.

+6 +6

3 2 2 4

+6 +6

3 2 2 2 7

Cr O + H O H Cr O

2Cr O + H O H Cr O

(axit cromic)

2. Mui cromat v icromat (CrO42- v Cr2O72-)

+ Mui cromat v icromat bn hn nhiu so vi dng axit v c tnh oxi hart mnh. c bit trong mi trng axit, mui Cr+6 b kh thnh mui Cr3+.

++6 +2 +3 +3

H2 2 22 7 4 2 4 4 3 4 3 2 4 2K Cr O + 6FeSO + 7H SO 3Fe (SO ) + Cr (SO ) + K SO + 7H O

+ Trong dung dch lun tn ti c 2 ion CrO42-

(mu vng) v Cr2O72-

(mu dacam) t trng thi cn bng-

+

+6OH2- 2-

2 7 4HCr O Cr O

(mu da cam) (mu vng)

CHNG 9: HA HC V VN PHT TRIN KINH T, X HI, MI TRNG

Cn lu cc vn sau:

1- Nhng ngun nng lng c xu th pht trin nng lng trong tng lai t gy nhim mi trng l: nng lng ht nhn, thy nng (nng lng nc), nng lng mt tri,..

2- Nhin liu sach gm: kh hiro, thy in, nng lng mt tri,

3- Cht gy nghin gm: ru, nicotin (c trong thuc l), cafein,

4- Cht ma ty gm: cocain, amphetanin, thuc phin,

5- Cc cht gy nhim khng kh l: CO, CO2, SO2, H2S, NOx, CFC, cc cht bi,

8- Cht ch yu gy ra hiu ng nh knh l : kh CO2

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