PTTT - Hoa Li - Giang

Phc trnh thc tp Ha l CNHH Hc k 1 nm hc 2011 - 2012

Nhm 10: V Trng Giang (2092127) Quch Hoi Tn (2092159) 1

B

AAB

V

VCC

Bi 1

XC NH BIN THIN NNG LNG T DO, ENTALPI, ENTROPI CA QU TRNH HO TAN BORAX TRONG NC

I. MC CH:

Trong bi thc tp ny s xc nh tan S ca mui t tan Borax cc nhit khc

nhau, t xc nh tch s ha tan spK ph thuc theo nhit . Sau bng phng

php th, s tnh c 000 ,, SGH ca s ha tan ny.

II. TM TT C S L THUYT:

mt nhit xc nh, mui Borax ha tan vo nc c cn bng ha tan sau: 274742 2)( OBNarOBNa

S( mol/l) 2S S

Mui Natri Borat ha tan vo nc l mt base trung bnh : OHBOHOHOB 247 332

274

S 2S

Bng phng php chun mt th tch bit ca dung dch Borax vi dung dch HCl

chun, chng ta tnh c nng ca anion 274OB .

332274 425 BOHHOHOB

Gi S l tan ca Borax th nng ca ion 274OB tm c trong qu trnh chun

vi HCl cng chnh l S v SNa 2

Khi ta c: spK = 32742

4SOBNa

Mt khc ta c : 00ln SHKRT sp

Suy ra : R

S

TR

HKsp

00 1.ln

T phng trnh ny, chng ta v th hm s ln spK theo bin s T

1, c ng thng

h s gc l : R

Htg

0

V tung gc l : R

S 0

Th TSH ,, 00 vo phng trnh : 000 STHG ta s tm c 0G .

Vy , qua vic kho st qu trnh ha tan ca Borax, ta xc nh c cc i lng

nhit ng ca qu trnh.

III. KT QU:

Theo nh lut ng lng: CAVA=CBVB



Khi [B4O72] = S =

2

BC =

8

25.0 AV(mol/L). Vi VA l th tch dung dch HCl c t buret

Bng s liu sau:

tC TK 1/T VHCl (ml) [B4O72] [Na

+]=2S Ksp=4S

3 lnKsp

50 323 0.00310 32.8 0.0010 0.0021 4.31E09 19.263 45 318 0.00314 28.4 0.0009 0.0018 2.80E09 19.695 40 313 0.00319 20.4 0.0006 0.0013 1.04E09 20.688

35 308 0.00325 17.5 0.0005 0.0011 6.54E10 21.148 30 303 0.00330 12.5 0.0004 0.0008 2.38E10 22.157

th s ph thuc ca lnKsp theo 1/T:

T th suy ra phng trnh ng thng:

lnKsp = 14166.T

1+ 47,48 => Suy ra : tg =

R

H 0 = 14166

molJHR

Htg /1,11777614166 0

0

molJSR

S/18,205314,8.68,2468,24 0

0

0G nhit chun 25 0 C (298K) 0G = 0H T 0S = 117776,1 205,18.(273 + 25) = 56632,46 J 56,63 KJ



Bi 2

XC NH KHI LNG PHN T BNG PHNG PHP NGHIM LNH

I. MC CH:

Xc nh khi lng phn t ca cht hu c da vo phng trnh nghim lnh.

II. C S L THUYT:

xc nh khi lng phn t ta da vo biu thc sau:

dd

dd

T

K

G

gM

.1000 (1)

Vi: 1000. 0

20 M

H

RTK

dd

dd

Kdd gi l hng s nghim lnh ch ph thuc vo bn cht ca dung mi. Vi dung

mi l nc th Kdd = 1,86.

III. KT QU:

1.Nc tinh khit:

Kt qu o nhit ng c ca nc tinh khit:

ng cong nhit - thi gian ca nc tinh khit:

t(s) 0 30 60 90 120 150 180 210 240 270

T(oC) 0.5 1.5 0.2 0.9 1 1.4 2.6 0.1 0.1 0.1

t(s) 300 330 360 390 420 450 480

T(oC) 0.1 0.1 0.1 0.1 0.1 0.1 0.1



2. ng saccaroz (C12H22O11):

Kt qu o nhit ng c ca ng saccarozo (C12H22O11):

ng biu din nhit theo thi gian ca dung dch saccarose

3. Cht X

Kt qu o nhit ng c ca cht X:

t(s) 0 30 60 90 120 150 180 210 240 270

T(oC) 0.3 0.2 0 0.9 0 0.3 0.3 0.4 0.4 0.4

t(s) 300 330 360 390 420 450 480

T(oC) 0.4 0.4 0.4 0.4 0.4 0.4 0.4

t(s) 0 30 60 90 120 150 180 210 240 270

T(oC) 0.5 0.1 1 1.8 2 2.5 2.6 2 2.3 3.3

t(s) 300 330 360 390 420 450 480 510 540 570

T(oC) 3.6 1.4 0.4 0.4 0.4 0.4 0.5 0.6 0.6 0.6

t(s) 600 630 660 690 720 750 780 810 840 870

T(oC) 0.7 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5



ng biu din nhit theo thi gian ca dung dch X

4. Khi lng ca ng saccaroz v cht X:

a. Khi lng ca ng sacaroz:

M = 1000.G

g

T

K = 1000.

50

2.

(0.3)(0,1)

1,86 = 372 g

b. Khi lng ca phn t cht X:

M = 1000.G

g

dd

dd

T

K

= 1000. 50

2.

(0.5)(0.1)

1.86 = 186 g



Bi 3 NGHIN CU CN BNG HO HC CA PHN NG

2Fe3+ + 2I- 2Fe2+ + I2

I. MC CH

Xc nh hng s cn bng ca phn ng ha hc:

2Fe3+ + 2I 2Fe2+ + I2

ti 2 nhit khc nhauv t tnh hiu ng nhit trung bnh ( H ) ca phn ng.

II. C S L THUYT

Biu thc ca hng s cn bng theo nng ca phn ng trn c dng:

223

222

][][

][][

IFe

IFeKc (1)

Xc nh gi tr hng s cn bng hai nhit khc nhau1,TC

K v 2,TC

K . T

c th xc nh hiu ng nhit trung bnh ( H ) ca phn ng trong vng nhit

kho st bng phng trnh ng p VantHoff:

21,

, 11.ln

2

1

TTR

H

K

K

TC

TC

III. KT QU

Ti 30C:

VNa2S2O30,01N (mL)

Thi gian phn ng (pht) Bnh 2 Bnh 4 Bnh 6

25 5.9 6.1 6.1

55 6.4 6.8 6.6

95 6.6 6.9 6.7

135 6.6 6.8 6.7

Bng s liu tnh ton:

Cht Bnh 2 Bnh 4 Bnh 6

Nng u

Nng cn bng

Nng u

Nng cn bng

Nng u

Nng cn bng

I2 0.000 0.0033 0 0.0034 0 0.0034

Fe2+ 0.000 0.0066 0 0.0068 0 0.0067

Fe3+ 0,015 0.0084 0,0165 0.0097 0,0135 0.0068

I 0,015 0.0084 0,0135 0.0067 0,0165 0.0098

Kc 28.87 37.22 33.86

Kc 33.32

Ti 40C:



VNa2S2O30,01N (mL)

Thi gian phn ng (pht) Bnh 2 Bnh 4 Bnh 6

25 6.8 7.3 6.7

55 7.1 7.8 6.8

95 7.2 7.9 6.8

135 7.2 7.9 6.8

Bng s liu tnh ton:

Cht

Bnh 2 Bnh 4 Bnh 6

Nng

u

Nng

cn bng

Nng

u

Nng

cn bng

Nng

u

Nng

cn bng

I2 0.000 0.0037 0 0.0039 0 0.0034

Fe2+ 0.000 0.0074 0 0.0078 0 0.0068

Fe3+ 0,015 0.0076 0,0165 0.0087 0,0135 0.0067

I 0,015 0.0076 0,0135 0.0057 0,0165 0.0097

Kc 59.91 96.49 37.22

Kc 64.54

S dng phng trnh ng p Vant Hoff, a c:

ln1,

, 2

Tc

Tc

K

K =

R

H.(

2

1

T

1

1

T)

H = ln1,

, 2

Tc

Tc

K

K.R.(

21

21

TT

TT

)

= ln32,33

54,64. 8,314 . (

313303

313.303

) = 52129 J= 52,13kJ



Bi 4:

NH LUT PHN B V CN BNG HO HC

I. MC CH:

Trong bi th nghim ny ta kho st s ha tan ca cht tan l Iod vo hai dung mi

khng trn ln l H2O v CCl4. Xc nh hng s phn b ca qu trnh ny.

II. C S L THUYT:

Mt cht tan A ha tan c c trong hai dung mi D1 v D2. Hai dung mi ny

khng ha tan vo nhau. Khi cho cht tan A vo hn hp 2 dung mi, lc mnh th cht tan A

s ha tan vo c 2 dung mi. Do 2 dung mi ny khng ha tan vo nhau nn chng s phn

lp, dung mi no nng hn s lng xung lp di. yn mt thi gian s ha tan cht

tan A vo 2 dung mi trn t cn bng. Lc , theo nh lut phn b th :

pbdd

dd KA

A

2

1

pbK : Hng s phn b, ph thuc vo bn cht ca cht tan, dung mi, nhit v

khng ph thuc vo nng .

III. KT QU

Bng kt qu:

Bnh 1 Th tch dung dch Na2S2O3 0,1N (mL) Nng

Lp di (1mL) Ln 1 Ln 2 Ln 3 Trung bnh

C1 = 0,45 4.4 4.5 4.5 4.5

Lp trn (10mL) Ln 1 Ln 2 Ln 3 Trung bnh

C2 = 0,005 0.6 0.5 0.5 0.5

Bnh 2 Th tch dung dch Na2S2O3 0,1N (mL) Nng

Lp di (1mL) Ln 1 Ln 2 Ln 3 Trung bnh

C1 = 0,14 1.5 1.4 1.4 1.4

Lp trn (5mL) Ln 1 Ln 2 Ln 3 Trung bnh

C2 = 0,084 4.2 4.1 4.2 4.2

Kpb = C2/C1 = 0,011

Tnh K (bnh 2):

[I2] = C1k =C1

0015,0005,0

45,014.0

1

2 C

Cmol/l

[KI3] = C2 [I2] = 0,084 0,0015 = 0,0825 mol/l

[KI] = [KI]0 [KI3] = 0,1 0,0825 = 0,0175 mol/l

K=

23

. IKI

KI= 3142,86



Bi 5: XC NH BC PHN NG

I. MC CH:

Trong bi ny chng ta s xc nh bc ring phn v bc tng qut ca phn ng:

2Fe3+ + 2I 2Fe2+ + I2

II. C S L THUYT:

Da vo phng php vi phn ca Van Hoff:

Gi s vn tc u ca phn ng c xc nh bng phng trnh :

21 3 000

n

I

n

Fet

CCkdt

dC

Ly logarit ta c

201

0 lglglglg 2n

I

n

Feot

CCkdt

dC

C nh mt trong hai nng ta s xc nh c n1 v n2. T xc nh bc chung ca

phn ng n = n1 + n2.

Xy dng th otdt

dC

theo 0lg C ta xc nh c n1 v n2

xc nh c vn tc thi im u ta s dng phng trnh kinh nghim sau :

tCx

11

Cx l nng mol ca Fe2+ sinh ra mi thi im t

t : thi gian phn ng ; , : hng s thc nghim

Ly o hm dt

dCx ti t=0 ta c :

1

0

tdt

dC; Xy dng th ta xc nh c hng s

thc nghim

III.TNH TON KT QU :

1) Chui phn ng 1 : Gi nng KI khng i

Bnh 1:

t giy V Na2S2O3

(mL) Cx 1/Cx 1/t

23 1 0.0001 10000 0.0122 82 2 0.0002 5000 0.0071

140 3 0.0003 3333.33 0.0045 220 4 0.0004 2500 0.0033 305 5 0.0005 2000 0.0026 392 6 0.0006 1666.67 0.0020 510 7 0.0007 1428.57 0.0016 630 8 0.0008 1250 0.0016



Bnh 2 :

t giy V Na2S2O3

(mL) Cx 1/Cx 1/t

19 1 0.0001 10000 0.0526 51 2 0.0002 5000 0.0196 89 3 0.0003 3333.33 0.0112

133 4 0.0004 2500 0.0075 181 5 0.0005 2000 0.0055 243 6 0.0006 1666.67 0.0041 322 7 0.0007 1428.57 0.0031 407 8 0.0008 1250 0.0025

Bnh 3 :

t giy V Na2S2O3

(mL) Cx 1/Cx 1/t

5 1 0.0001 10000 0.2000 24 2 0.0002 5000 0.0417 52 3 0.0003 3333.33 0.0192 85 4 0.0004 2500 0.0118

123 5 0.0005 2000 0.0081 168 6 0.0006 1666.67 0.0060 221 7 0.0007 1428.57 0.0045 279 8 0.0008 1250 0.0036



Bnh 4:

t giy V Na2S2O3

(mL) Cx 1/Cx 1/t

2 2 0.0002 5000 0.5000 16 4 0.0004 2500 0.0625 42 6 0.0006 1666.67 0.0238 82 8 0.0008 1250 0.0122

108 10 0.0010 1000 0.0093 161 12 0.0012 833.333 0.0062 218 14 0.0014 714.286 0.0046 291 16 0.0016 625 0.0034

Bng gi tr lg1/ theo lgC0

Bnh 1/ [Fe3+]0 log1/ log[Fe3+]0

1 79420 1,3.105 0.00167 -4.8999 -2.7773 2 11750 8,5.105 0.00333 -4.0700 -2.4776 3 42437 2,4.105 0.005 -4.6277 -2.3010 4 8112 0.00012 0.00667 -3.9091 -2.1759



Vy phn ng c bc 1,2 bc 1 theo Fe3+

2) Chui th nghim 2: Gi nng Fe3+ khng i

Bnh 1 :

t giy V Na2S2O3

(mL) Cx 1/Cx 1/t

33 1 0.0001 10000 0.0303 133 2 0.0002 5000 0.0075 250 3 0.0003 3333.33 0.0040 407 4 0.0004 2500 0.0025 629 5 0.0005 2000 0.0016 883 6 0.0006 1666.67 0.0011 1158 7 0.0007 1428.57 0.0009 1467 8 0.0008 1250 0.0007



Bnh 2

t giy V Na2S2O3

(mL) Cx 1/Cx 1/t

6 1 0.0001 10000 0.1667 14 2 0.0002 5000 0.0714 54 3 0.0003 3333.33 0.0185 97 4 0.0004 2500 0.0103

142 5 0.0005 2000 0.0070 207 6 0.0006 1666.67 0.0048 263 7 0.0007 1428.57 0.0038 341 8 0.0008 1250 0.0029

Bnh 3

t giy V Na2S2O3

(mL) Cx 1/Cx 1/t

3 1 0.0001 10000 0.3333 13 2 0.0002 5000 0.0769 27 3 0.0003 3333.33 0.0370 44 4 0.0004 2500 0.0227 66 5 0.0005 2000 0.0152 90 6 0.0006 1666.67 0.0111

116 7 0.0007 1428.57 0.0086 148 8 0.0008 1250 0.0068



Bnh 4:

t giy V Na2S2O3

(mL) Cx 1/Cx 1/t

2 3 0.0003 3333.33 0.5000 18 6 0.0006 1666.67 0.0556 52 9 0.0009 1111.11 0.0192 97 12 0.0012 833.333 0.0103

157 15 0.0015 666.667 0.0064 237 18 0.0018 555.556 0.0042 349 21 0.0021 476.19 0.0029 497 24 0.0024 416.667 0.0020

Bng gi tr lg1/ theo lgC0

Bnh 1/ [I]0 log1/ log[I]0

1 28606 3,4958.105 0,0025 -4,4565 -2,6021 2 50465 1,9816.105 0,005 -4,7030 -2,3010 3 25726 3,8871.105 0,0075 -4,4104 -2,1249 4 5360 0,00018657 0,01 -3,7292 -2,0000

===> Phn ng bc 0,996 bc 1 theo I-

Vy: Phn ng c bc 1 theo Fe3+ , bc 1 theo I- v bc 2 tng qut.



Bi 6

KHO ST TC THU PHN ESTER.

XC NH NNG LNG HOT HA CA PHN NG I. MC CH:

Kho st tc thy phn ester nhiu nhit t xc nh nng lng hot ha

ca phn ng.

II. C S L THUYT:

Trong bi th nghim ny, ester c chn l acetat etyl. y l phn ng bc mt nn:

atk

xa lg303.2

)lg( 1 (*)

a: nng u ca acetat etyl ; ax: nng ca acetat etyl thi im t.

Theo di tc phn ng bng cch nh phn lng acid CH3COOH sinh ra ti tng thi

im.

Gi V l th tch dung dch NaOH cn dng chun 10ml mu lc phn ng xy

ra hon ton ; V0 l th tch dung dch NaOH cn dng chun 10ml mu lc bt u

phn ng ; Vt l th tch dung dch NaOH cn dng chun 10ml mu thi im t.

V th tch t l vi nng nn phng trnh (*) c dng:

)lg(303.2

)lg( 01 VVtk

VV t

V ng biu din )lg( tVV theo t, suy ra k1 t h s gc ca ng biu din.

III. KT QU TH NGHIM

1. Thc hin phn ng 300C

V = VT1+ VT2

VT1: l th tch NaOH cn nh phn HCl trong 10ml mu hn hp thi im t.

VT2: l th tch NaOH cn nh phn CH3COOH trong 10ml mu hn hp thi im

phn ng hon ton.

* Tm VT1:

Trong hn hp gm: 5ml ester acetat etyl + 95ml HCl = 100ml. Nng trong hn

hp ca HCl l: CN = (0,2.95)/100 = 0,19N

Th tch NaOH cn nh phn HCl l:

CB.VB=CA.VA hay 0,1.VB=0,19.10 VB = 19 ml => Vy VT1= 19ml

* Tm VT2: VT2=(5000d)/M =(5000.0,897)/88 = 50,96 ml V =19+ 50.97 = 69.97 ml

T, pht Vt, ml V tVV )lg( tVV

5 19.2

69.97

50.77 1.7056 15 19.7 50.27 1.7013 25 20.5 49.47 1.6943 35 21.1 48.87 1.6890 45 21.8 48.17 1.6828 55 22.2 47.77 1.6792



)lg(303.2

)lg( 01 VVtk

VV t

th biu din )lg( tVV theo T

Ta c:

H s gc ca ng thng = 0,0006 = k1/2,303 =====> k1 = 1,38.10-3 (s1)

2. nhit 400C:

T, pht V1, ml V tVV )lg( tVV

05 18.8

69.97

51.17 1.7090 15 21.4 48.57 1.6864 25 23.1 46.87 1.6709 35 25.2 44.77 1.6510 45 27.4 42.57 1.6291 55 30.3 39.67 1.5985

H s gc ca ng thng = 0,0021= k2/2,303 ==> k2 = 4,8.10-3 (s1)

3. Nng lng hot ha Ea

42,7kJ/mol J/mol42686

313

1

303

1

10.38,1

10.8,4lg.314,8

11

lg

11

303.2lg

3

3

21

1

2

211

2

TT

k

kR

E

TTRT

E

k

k

a

a



Bi 7:

XC TC NG TH PHN NG PHN HY H2O2 I. MC CH

Xc nh hng s tc , chu k bn hy, nng lng hot ha ca phn ng phn hy

H2O2 vi ion Cu2+ l xc tc.

II. C S L THUYT

H2O2 t phn hy xy ra theo hai giai on:

1. HOOH O2 + 2H+ (giai on chm)

2. HOOH + 2H+ 2H2O

2H2O2 2H2O + O2

Tc tng qut ca phn ng c xc nh bi giai on chm v do phn ng xy

ra theo bc 1. ln (a-x) = -kt + lna

Vi a: nng H2O2 ban u; x: nng H2O2 tham gia phn ng

Lc u H2O2 xem nh cha phn hy v em chun vi KMnO4: ta c s lin h gia

a, ax, Vo, Vt (l th tch lc u v theo tng thi gian chun ca KMnO4) l:

to

o

VV

V

xa

a

III. KT QU TH NGHIM

a. Thc hin phn ng 30oC:

t, pht 0 5 10 15 20 30

4KMnOV 6.1 5.0 4.4 4.0 3.8 3.5

ln4KMnO

V 1.81 1.61 1.48 1.39 1.34 1.25

th ln4KMnO

V theo t :

H s gc ca th l 0,017, suy ra 017,0)017,0( k

Vy hng s vn tc phn ng l k = 0,017



Tnh chu k bn phn hy:

76,40017,0

693,0

b. Thc hin phn ng 40oC:

t, giy 0 5 10 15 20 30

4KMnOV 16

14.7

14 13,

2 12,

5 11

ln4KMnO

V 2,773

2,688

2,639

2,580

2,526

2,398

th ln4KMnO

V theo t :

K2 = 0,047 2= 0,693/k = 14,74.

Nng lng hot ha:

121

2 11lnTTR

E

k

ka

303

1

313

1

017,0

047,0ln

R

Ea

Ea = 80184 (J/mol)



Bi 8:

XC NH G, H V S CA MT PHN NG IN HA

I. MC CH:

Xc nh nhng c tnh nhit ng hc bng k thut in ho.

II. C S L THUYT:

S thay i nng lng t do ca mt phn ng in ho lin quan n th E ca h

in ho: G = nFE (1)

n l s electron trao i cho 1 mol cht phn ng

F hng s Faraday

Nu in th c o nhng nhit khc nhau, s thay i Entropy p sut khng

i c biu din bng phng trnh:

dT

GdS

(2)

Th (1) vo (2):

dT

nFEdS

dT

dEnFS (3)

T (3) ta thy dT

dE l h s gc ca th th s ph thuc th E vo nhit .

Trong th nghim ny chng ta kho st mt h in ho gm 2 in cc Zn2+/Zn v

Cu2+/Cu tip xc nhau qua mt cu mui KCl bo ho.

Zn 2e Zn2+

Cu2+ + 2e Cu

Cu2+ + Zn Cu +Zn2+

S ph thuc ca E vo nng , nhit ,... c xc dnh bng phng trnh Nernst:

tc

sp

pupua

a

nF

RTEE ln0 (5)

Trong hu ht cc trng hp hot thng c thay th bi nng . Phng trnh

(5) c vit: tcsp

nEE pupu lg

059,00 (6)

Khi nng [Zn2+] v [Cu2+] trong dung dch nh nhau th tcsp

lg gim ti 0. Trong

iu kin ny, th E ca pin bng vi E0. T E da vo (2) ta tnh c G.

Ngoi ra trong th nghim ny, gi tr th cng c o nhng nhit khc nhau.

III. KT QU TH NGHIM:

Nhit oC 6,5 26 50

in th E 1,056 1,06 1,064



molJdT

dEnFS /6,38102965002 4 .0K

26oC:

G = nFE = 2.96500.1,06 = 204580 J/mol

H = G + TS = 204580 + 299.38,6 = 193038,6 J/mol 193,04 KJ/mol

IV. Tr li cu hi:

1. Trong nguyn t Galvani:

Ti anod xy ra qu trnh oxi ha.

Ti catod xy ra qu trnh kh.

Dng electron chy t anod sang catod.

2. Mt pin c kt qu :

toC 26,5 2,5 80

E (V) 0,465 0,454 0,493

26.5oC:

5,2680

465,0493,0

dT

dE0,0005

KVdT

dE 0/0005,0

../5,960005,0.96500.2 05,299 0

KmolJdT

dEnFS

K

molJnFEG

K/89745465,0.96500.205,299

molJSTGHKKK

/25,60843000 5,2995,2995,299 60,84 KJ/mol



Bi 9

KHO ST TC THU PHN ESTER. XC NH NNG LNG HOT HA CA PHN NG

I. MC CH:

Kho st s hp th acis axetic trong dung dch trn than hot tnh v thit

lp ng ng nhit hp th tng ng.

II. C S L THUYT:

Trong bi ny, chng ta nghin cu nh hng ca nng cht tan CH3COOH ln

hp ph ca n trn than hot tnh nhit khng i trong dung mi nc.

hp ph a (mmol/g) ln b mt than c th tnh t cng thc: 1000..0 Vm

CCa

C0, C l nng u v nng ti cn bng hp ph ca dung dch acid axetic

(mol/lit); V th tch dung dch trong xy ra s hp ph; m khi lng cht hp ph.

Phng trnh Langmuir: maxmax

1

kaa

C

a

C . Ta c th xc nh amax v k1 theo th.

Phng trnh kinh nghim Freundlich: Cka lg2

1lglg

Do c th xc nh hng s kinh nghim kF v n t s liu thc nghim.

III. TIN HNH & KT QU TH NGHIM

T dung dch CH3COOH 2M pha long thnh nhng dung dch c nng nh sau:

Bnh 1 2 3 4 5 6

V dung dch (ml) 200 200 200 200 200 200

V CH3COOH 2M 3 6 9 12 15 20

Nng mol/l 0.03 0.06 0.09 0.12 0.15 0.2

Chun li dung dch axit pha bngdung dch NaOH vi thuc th phenolphtalein.

Bnh 1 2 3 4 5 6 V (ml) NaOH 0,1N 6.1 12.2 18.5 12.3 15.9 21.4 Vo axit (ml) c chun 20 20 20 10 10 10 Nng axit (Co) 0.031 0.061 0.093 0.123 0.159 0.214

Sau khi thm than hot tnh, chun li bng NaOH.

Bnh 1 2 3 4 5 6 V (ml) NaOH 0,1N 3.6 9.2 15.5 10.7 14 19.3 V1 axit (ml) c chun 20 20 20 10 10 10 Nng axit (C) 0.018 0.046 0.0775 0.107 0.14 0.193



Tnh ton cc gi tr

Bnh

Gi tr 1 2 3 4 5 6

a 0.417 0.500 0.500 0.533 0.633 0.700

C 0.021 0.058 0.093 0.115 0.155 0.215 C/a 0.050 0.116 0.186 0.216 0.245 0.307

lga 0.380 0.301 0.301 0.273 0.198 0.155

lgC 1.678 1.237 1.032 0.939 0.810 0.668

amax = 1/1,301 = 0,769 kLangmuir = 1/ (0,044.0,769) = 29,55.



n = 1/0,21 = 4,76 k = 0,9

* Nhn xt tnh hp th acid acetic ca than hot tnh:

hp ph acid acetic ca than hot tnh tng khi nng ban u ca dung dch

acid acetic tng v ngc li.

Vy, hp ph ca than hot tnh i vi dung dch acid acetic t l thun vi nng

ban u ca dung dch acid acetic.



Bi 10

KHO ST CC H KEO I. MC CH:

Kho st s keo t ca Fe(OH)3 bng cht in ly v quan st s thm tch ca keo qua

mng bn thm (bong bng heo).

II KT QU TH NGHIM:

1. iu ch keo Fe(OH)3:

Ly 200ml nc ct cho vo bnh nn 250, un si. Tt bp ri thm tng git dung

dch FeCl3 1N n khi ht 5ml.Ta c keo dng mu nu sm.

FeCl3 + 3H2O = Fe(OH)3 + 3HCl

B mt ht keo b phn ng mt phn:

Fe(OH)3 + HCl FeOCl + 2H2O

FeOCl FeO+ +Cl

mFe(OH)3 + n FeO+ + nCl [mFe(OH)3.nFeO

+ (nx)Cl ]x+ .xCl

Micell keo dng

Sau ngui keo trong khng kh.

2. Keo t keo Fe(OH)3 bng cht in ly:

nh du + nhng ng b keo t v du nhng ng khng b keo t.

ng nghim 1 2 3 4 5 6 7 8 9 10

Keo Fe(OH)3 5 5 5 5 5 5 5 5 5 5

Nc ct 4.5 4 3.5 3 2.5 2 1.5 1 0.5 0

Cht in ly 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5

Nhn xt KCl + + + +

Nhn xt K2SO4 + + + + + + + + +

Ngng keo t cho mi cht in ly, tc nng ca cht in ly ti thiu trong ng gy

nn keo t:

Vi v N l th tch (ml) v nng ban u (lg/l) ca cht in ly ng u tin b

keo t.

V l tng th tch ho cht trong ng nghim (10ml).

Ngng keo t i vi cht in ly KCl: 105010

10.3.5,3 3 mmol/l = 1,050 mol/l

Ngng keo t i vi cht in ly K2SO4 110

10.01,0.1 3 mmol/l

3. Keo a lng:

a. iu ch:

V

N 310..



Keo tinh bt: 0.5g tinh bt + 100ml nc ct. un nh, khuy u n khi tinh bt

tan ht. Nhc xung ngui.

Keo anbumin: ly mt lng trng trng g + 100ml nc ct, khuy u l c keo

anbumin.

b. Thm tch keo:

ng 1: th bng dung dch Ba2+ , thy xut hin kt ta mu trng. Nh vy, ion SO42

thm tch ra ngoi.V SO42 l mt ion nn kch thc nh do c th khuch tn qua

mng bn thm ra mi trng bn ngoi.

ng 2: th bng dung dch iod, khng c hin tng. Nh vy, tinh bt khng b thm

tch do tinh bt dng dung dch keo nn kch thc ht to. Do khng khuch tn c

qua mng bn thm.

c. Bt:

ng nghim Th tch nc + bt (ml) bn ca bt (s)

ng 1 33 35

ng 2 38 79

ng 3 46 229

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