chuan do axit bazo.doc

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<p>I</p> <p>MC LC</p> <p>2PHN M U</p> <p>21. L Do Chn Ti</p> <p>32. Mc Tiu Ca Ti.</p> <p>33. Nhim V Ca Ti</p> <p>34. i Tng Nghin Cu</p> <p>35. Phm Vi Nghin Cu</p> <p>5PHN NI DUNG</p> <p>5Chng I. C S L Thuyt Ca Phng Php Chun Axit Bazo n Chc</p> <p>51. Khi Nim Chun Axit Bazo V Cc Vn Lin Quan.</p> <p>5Dung dch chun</p> <p>6Cht ch th</p> <p>62. Mt S Phng Php Chun Axit Bazo.</p> <p>62.1. Chun Axit Mnh Bng Bazo Mnh.</p> <p>82.2. Chun Bazo Mnh Bng Axit Mnh.</p> <p>82.3. Chun Axit Yu n Chc Bng Bazo Mnh.</p> <p>92.4. Chun Bazo Yu n Chc Bng Axit Mnh.</p> <p>11Chng II. Mt S Bi Tp V Chun Axit Bazo n Chc.</p> <p>11II.1. Chun Axit Mnh Bng Bazo Mnh</p> <p>17II.2. Chun Bazo Mnh Bng Axit Mnh</p> <p>22II.3. Chun n Axit Yu Bng Bazo Mnh</p> <p>29II.4. Chun Bazo Yu Bng Axit Mnh.</p> <p>38PHN KT LUN</p> <p>39TI LIU THAM KHO</p> <p>PHN M U1. L Do Chn Ti.</p> <p>Trong x hi vn minh v pht trin nh hin nay, mi sinh vin trong cc trng i hc cn khng ngng nghin cu khoa hc v nghin cu nhng kin thc thng tin v ang c cp nht trn h thng cng ngh thng tin. Nghin cu khoa hc ca sinh vin gp phn khng nh cho sinh vin bc tip trn con ng chim lnh tri thc khoa hc k thut ca thi i. cc nghin cu khoa hc ca sinh vin bao gm cc phm vi v nhiu lnh vc khc nhau. Trong khoa hc t nhin ang c nghin cu di nhiu hnh thc. nhiu ti c cng b v cng nhn. mt trong nhng lnh vc nghin cu ca sinh vin l lnh vc ha hc v ha hc phn tch cng khng phi l mt ngoi l. ha hc phn tch l mt mn hc chuyn ngnh rt quan trng i vi sinh vin khoa ha hc. Hc phn tch ng vai tr rt quan trng i vi cc ngnh khoa hc khc cng nh trong i sng. N i su vo nghin cu v phn tch cc thnh phn ha hc ca cc cht v t cng bit mt s c tnh ca cht . i vi ti l sinh vin ang hc ti mi trng s phm vi kin thc cn nhiu hn ch nn ti chn ti ny tm ra mi lin h gia l thuyt v thc hnh cng nh rn luyn k nng cn thit trong vic gii cc bi tp v ha hc phn tch.</p> <p> ti ny gip cho cc sinh vin h thng ha li kin thc ca mnh i vi mn hc ha hc phn tich ni chung v phn chun axit-bazo ni ring. N mang tnh tin cho cc nghin cu rng ri hn v i su hn trong vn ny. y l ti liu quan trng cho sinh vin v cc gio vin nghin cu, tip thu lm cho kin thc phong ph hn, bit r hn v phn tch cc thnh phn ha hc ca cc cht trong t nhin, thin nhin. Phng php phn tch, chun ny cho ta bit c tinh khit ca mt cht, long hay c ca mt dung dch c sn trong phng th nghim m ta cha xc nh c nng ca n. Tnh c phn trm ca cht c trong mt dung dch m ta cha xc nh c.2. Mc Tiu Ca Ti.</p> <p>Nm vng l thuyt phn tch axit-bazo n chc.</p> <p>Bit mt s dng bi tp lm tin ng dng vo thc hnh</p> <p>Khai thc cc phng php gii bi tp i vi cc dng bi tp khc nhau</p> <p>Hon thin kin thc v phn tch axit- bazo</p> <p>3. Nhim V Ca Ti</p> <p>Nghin cu mt s bi tp v vn axit bazo n chc.</p> <p>Nghin cu l thuyt tng quan chun , phn tch nh lng i su vo phn tch axit bazo.Nghin cu gii php ti u gii bi tp, ng dng vo thc hnh nhanh chng, t tn km thi gian.4. i Tng Nghin CuCc bi tp ha hc phn tch</p> <p>L thuyt, cc cng thc phn tch c bn</p> <p>5. Phm Vi Nghin CuCc loi gio trnh ca ha hc phn tch hin nay</p> <p>L thuyt v bi tp v ha hc phn tch. Cc ngun thng tin google</p> <p>6. Phng Php Nghin CuPhng php phn tch tng hp</p> <p>Phng php quan st</p> <p>7. NghaGip cho sinh vin h thng ha li kin thc v chun axit bazo</p> <p>Nm c mt s dng bi tp cn thit v phng php gii c chng.PHN NI DUNGChng I. C S L Thuyt Ca Phng Php Chun Axit Bazo n Chc1. Khi Nim Chun Axit Bazo V Cc Vn Lin Quan.Phng php phn tch chun da trn phn ng ha hc nh</p> <p> y, A l cht cn phn tch, B l thuc th c nng bit c dng phn ng vi A, gi l cht chun. A v B u dng dung dch. Thng thng B c ng trong Buret v khi c nh git t t vo dung dch cha cht phn tch. Qu trnh gi l s nh phn hay php chun . Thi im khi cho lng cht B vo phn ng vi cht A gi l im tng ng. bit c khi no dng chun ngi ta dng cht ch th. Cn c vo s i mu ca cht ch th ta kt thc qu trnh chun . im kt thc chun c th trng hoc khng trng vi im tng ng. Cn chn cht ch th sao cho im kt thc cng gn im tng ng cng tt. xc nh im tng ng trong phng php phn tch chun , ngi ta cn thng qua php o mt s i lng ha l nh in th, dn in, mt dng in trong dung dch trong qu trnh chun .Dung dch chun c c kt qu phn tch chnh xc, mt trong nhng yu cu quan trng hng u l phi c c dung dch chun c nng chnh xc. Dung dch chun u tin c chun b bng mt trong hai cch sau:1. cn chnh xc ha cht c chn pha ch dung dch chun, sau ha tan n v pha thnh dung dch c th chnh xc.2. cn chnh xc ha cht c chn sau pha ch thnh dung dch. Dung dch ny dc dng chun b dung dch u tin phi l nhng ha cht c tinh khit cao, c cng thc ha hc xc nh v bn vng trong iu kin bo un bnh thng. ha cht ny c phn t lng cng ln cng tt v s gim sai s tng i ca php cn.Cht ch th</p> <p>Cc cht ch th dng trong phng php chun axit bazo phi tha mn yu cu c bn l s i mu ca cht ch th phi thun nghch vi s bin i pH trong dung dch trong qu trnh chun . Mun vy bn thn cht ch th l nhng axit hoc bao hu c yu. ni chung cu trc ca cc cht ch th u rt phc tp v chuyn t dng axit sang dng bazo u c km theo s chuyn v ni phn lm thy i mu sc ca cht ch th. Ty theo cu trc ca cht ch th c th c in tch khc nhau. C th phn cc cht ch th thng lm ba nhm:- cc cht ch th thuc loi phtalein: phenol phtalein, thimol phtalein, naphtol phtalein- cc sunfon phtalein: phenol , brom phenol xanh, crezol - cc hp cht bazo: metyl da cam, tropeolin OO, metyl , trung tnh, congo , metyl vng2. Mt S Phng Php Chun Axit Bazo.Cc phng php phn tch u da vo s thn trng v sch s khi lm vic, chun b mu, ng n v chnh xc.2.1. Chun Axit Mnh Bng Bazo Mnh.</p> <p>Cng thc tnh p l:p = s ng lng gam cht cn chun A/s ng lng gam ca dung dch chun B </p> <p>Vi p trn cho thy:</p> <p>Ti im tng ng th p=1Trc im tng ng th p1</p> <p>Trc im tng ng ( C.VC0.V0)</p> <p>Sai s chun </p> <p>2.2. Chun Bazo Mnh Bng Axit Mnh.Trc im tng ng ( C.V pH = 14 pOHTi im tng ng ( C.V=C0.V0): khi ny ton b lng kim b trung ha bi axit. Do dung dch trung tnh, pH=7</p> <p>Sau im tng ng ( C.V&gt;C0.V0)</p> <p> =&gt; pH = 14 pOHSai s trong qu trnh chun :</p> <p>2.3. Chun Axit Yu n Chc Bng Bazo Mnh.Khi dung dch l dung dch axit nguyn cht th:</p> <p> vi Ka l hng s cn bng ca dung dch axit ti lc cn bngTrc im tng ng ( C.VC0.V0)</p> <p>Cng thc tnh sai s tng i:</p> <p>2.4. Chun Bazo Yu n Chc Bng Axit Mnh.Khi dung dch l dung dch axit nguyn cht th pH ca dung dch c tnh theo cng thc:</p> <p>Suy ra</p> <p>Cn khi cho axit vo nhng cha trung ha lng bazo trong dung dch c chun th pH c tnh theo cng thc:</p> <p> Suy ra pH = 14 - pOHKhi lng axit cho vo trung ha lng bazo yu th khi pH ca dung dch s &lt; 7 v c tnh theo cng thc:</p> <p>Vi Ka l hng s cn bng ca axit lin hp ca bazo yu</p> <p>V Ca l nng ca axit lin hp ca bazo yu Khi lng axit cho vo b d ra th pH ca dung dch c tnh theo cng thc:</p> <p> suy ra </p> <p>Vi qu trnh chun ny th cng thc tnh sai s tng i ca qu trnh ny l:</p> <p> trc im tng ng th ta c q 0 v h = [H+]Chng II. Mt S Bi Tp V Chun Axit Bazo n Chc.II.1. Chun Axit Mnh Bng Bazo MnhBi 1.a. Chun 25ml dung dch HCl bng dung dch NaOH 0.05M. Tnh nng HCl nu th tch dung dch NaOH dng l 17,50ml.</p> <p>b. Tnh bc nhy chun nu chp nhn sai s ca php chun l 0,2%</p> <p>c. Nu kt thc vic chun trn ti pH = 4,0 thi sai s chun bng bao nhiu? (5)Ta c phn ng chun : HCl + NaOH NaCl + H2O</p> <p>V HCl, NaOH l axit, bazo n chc nn CM = CN</p> <p>Theo quy tc ng lng ta c:</p> <p> CNaOH.VNaOH = CHCl.VHCl CHCl = b. dng ng cong chun </p> <p>Ta c pH0 ca dung dch HCl 0.035M l: pH = -log(0.035) = 1.456</p> <p>Theo cng thc tnh sai s ca php chun l:</p> <p>q = </p> <p>u bc nhy CHCl &gt;&gt; CNaOH khi q = -0.2% </p> <p>-210-3 = - </p> <p>Ta c pH ti im tng ng l</p> <p>Sau im tng ng th CNaOH &gt;&gt;CHCl nn q = +0.2%</p> <p>210-3 = - </p> <p>Vy php chun c sai s th kt thc chun trong khong pH = ngha l bc nhy trong khong 4.4 n 9.6ppH</p> <p>01.456</p> <p>0.984.4</p> <p>17</p> <p>1.029.6</p> <p>c. Kt thc chun khi pH trong dung dch l pH = 4.0 th ta c sai s ca php chun l:</p> <p>Bi 2. V ng nh phn khi chun 100ml dung dch HCl 0.1M bng dung dch NaOH 0.1M (1)Phn ng chun : </p> <p>Theo nh lut ng lng ta c: </p> <p>ml</p> <p>Khi cha thm NaOH, trong dung dch l HCl nguyn cht th pH ca HCl bng:</p> <p>Khi thm 50ml dung dch NaOH, trung ha c mt na lng HCl (p = -0.5)</p> <p>suy ra pH = 1.48</p> <p>Khi thm 99.9ml NaOH vo trong dung dch HCl th pH ca dung dch l (q = 0.1%):</p> <p> suy ra </p> <p>Khi thm 100ml dung dch NaOH ngha l p=1 trung ha vi axit HCl th pH= 7.0</p> <p>Khi thm 100.1ml NaOH (p=1.001)</p> <p> Suy ra pH = 9.7Khi thm 110ml dung dch NaOH, d 10ml NaOH th p =1.1</p> <p> suy ra pOH = 2.32 nn pH = 11.68Bi 3. Chun 100ml dung dch HNO3 1,00.10-3M bng dung dch NaOH 2,00.10-3M. tnh pH ca dung dich sau khi thm. (1)a. 49,98ml NaOH</p> <p>b. 50,03ml NaOH</p> <p>Ta c phng trnh chun :</p> <p>Theo nh lut ng lng ta c:</p> <p>a.Khi thm 49.98ml NaOH, th khi l trc im tng ng nn [H+]&gt;&gt;[OH-] do </p> <p>Vy pH = 6.57b.Khi thm 50.03ml NaOH th khi ny l sau im tng ng suy ra [OH-]&gt;&gt;[H+] do </p> <p> pOH = 6.4 suy ra pH = 7.6</p> <p>Bi 4. Tnh sai s khi chun 50.00ml HCl 0.05M bng dung dch NaOH 0.01M nu chun n xut hin mu vng ca cht ch th Metyl da cam (pT = 4.4) (1)Theo cng thc tnh sai s ta c:</p> <p>Bi 5.chun dung dch HCl 0.1M bng dung dch NaOH cng nng . Tnh sai s chun nu kt thc chun khi i mu Meetyl t hng sang vng. (pT = 6) (1)Khi ny qu trnh chun cha n im tng ng ngha l lc ny [H+]&gt;&gt;[OH-].</p> <p>Theo cng thc tnh sai s ta c:</p> <p>Bi 6.Chun 100ml dung dch HCl bng dung dch NaOH 1.00 khi thm 45.00ml dung dch NaOH th pH ca dung dch thu c bng 5.00. tnh nng ca dung dch HCl. (1)V NaOH l bazo n chc nn </p> <p>V pH = 5.00 &lt; pHt = 7 nn lc ny </p> <p>Vi pH = 5.00 suy ra [H+] = 10-5M</p> <p>II.2. Chun Bazo Mnh Bng Axit Mnh</p> <p>Bi 1. Chun 50ml dung dch NaOH n mu da cam ca Metyl da cam (pT = 4.00) th phi dng 80ml dung dch HCl 2.10-3M. tnh nng dung dch NaOH? (1)Ta c phng trnh chun :</p> <p>Khi Meetyl da cam i mu thnh da camcos pT = 4 tng ng vi nn </p> <p>Vy nng ca dung dch NaOH l 3.46.10-3M.Bi 2.Thm 40.0ml dung dch HCl vo 50.0ml dung dch NaOH th pH ca dung dch thu c bng 10. Nu thm tip 5ml dung dch HCl na th pH = 3.(1)a.Tnh nng ca HCl v NaOH.b.Tnh th tch HCl phi cho vo dung dch NaOH trn lm mt mu Phenol phtalein (pT = 8.00)Ta c phng trnh chun :</p> <p>a.Khi pH = 10 th nng [H+] = 10-10M nn cn xa im tng ng</p> <p>Suy ra </p> <p>(1)Khi thm 5.0ml HCl th pH = 3 khi ny th chun sau v xa im tng ng.</p> <p>(2)T (1) v (2) ta c h phng trnh:</p> <p>Vy nng ca dung dch HCl = 0.0208M v ca NaOH = 0.01682M</p> <p>b. lm mt mu phenol phtalein c pT = 8 suy ra ta c </p> <p>vi sai s </p> <p>Vy th tch HCl cn dng l:</p> <p>Bi 3.Tnh bc nhy pH ca php chun dung dch Ba(OH)2 2.10-3M bng dung dch HCl 5,00.10-3M nu chp nhn sai s chun l (1)Ta c phng trnh chun :</p> <p>V Ba(OH)2 l bazo a chc nn CN=2CM=4.10-3pH trc khi chun l pOH = -log(OH-)=2,4 pH= 11,6</p> <p>trc im tng ng th h= [H+] v q = -0,2%</p> <p>t iu kin h pH = 8,65Sau im tng ng [H+]&gt;&gt;[OH-] v q = 0,2%</p> <p> pOH = 8,65 =&gt; pH = 5,53</p> <p>vy bc nhy trong php chun ny l pH = 8,655,53Bi 4: chun 50ml dung dch Ba(OH)2 bng dung dch HCl 0,02M i mu Metyl (pT = 5) th phi dng ht 35ml HCl. Tnh chnh xc nng mol/lt ca dung dch Ba(OH)2? (1)Ta c </p> <p>Sai s l:</p> <p>Bi 5. chun dung dch NaOH bng dung dch HCl 0,02M c th dng metyl da cam v metyl lm cht ch th c khng nu chp nhn sai s khng vt qu 0,2%Ta c phng trnh chun :</p> <p>NaOH + HClNaCl + H2OpH lc cha chun l:pOH =-log(CNaOH)=-log0,01 = 2</p> <p> pH = 12</p> <p>pH u bc nhy l:</p> <p> EMBED Equation.3 t iu kin h</p>