2016 02 24 (30) Tricng Dgi hpc Tra Vinh MIX LiJC Ni dung Trang PHAN 1 PHAN T1CH DINH T1NH 2 BAI 1 XAC DINH CAC CATION NHOM I (Ag+, Pb2+, Hg22+) 2 BAI 2 XAC DINH CAC CATION NHOM II (Ba2+, Ca2+) 5 BAI. 1) Thuốc thử nhóm TT nhóm: Dung dịch HCl 2N. Hiện tượng: Xuất hiện kết tủa trắng. Phương trình (03): Ag+ + HCl AgCl + H+ Pb2+ + 2HCl PbCl2 + 2H+ Hg22+ + 2HCl Hg2Cl2 + 2H+
Tric&ng Dgi hpc Tra Vinh HĨA PHÂN TÍCH MIX LiJC Ni dung Trang PHAN 1: PHAN T1CH DINH T1NH BAI XAC DINH CAC CATION NHOM I (Ag+, Pb2+, Hg22+) BAI XAC DINH CAC CATION NHOM II (Ba2+, Ca2+) BAI XAC DINH CAC CATION NHOM III (Zn2+, A13+) * ATION NHOM V (Mg+2, Cu2+, Hg2±) BAI XAC DINH CAC C BAI XAC DINH CAC CATION NHOM VI (NH4 , K+, Nat) 10 BAI XAC DINH CAC ANION NHOM I (Cr, Br-, F, SCN-) 14 BAI XAC DINH CAC ANION NHOM III (NO3 , C2042-) 20 PHAN 2: PHAN TiCH DINH LliONG 24 BAT! DI CU'ONG vt PHAN TI CH KHOI LU'ONG 24 BAI PHYONG PHAP PHAN T1CH THE TiCH 34 BAI DUNG DICH CHUAN DO 41 BAI PHIIONG PHAP ACID - BASE 49 BAI PHUONG PHAP OX! HOA - KHO 57 BAI PHYONG PHAP KET TUA 68 TAI LIEU THAM KHAO 75 Tai lieu on thi tuyen sinh mon: Hoa Phan Tich Trtrang Dgi h9c Tra Vinh PHAN PHAN TiCH DINH TiNH Bai XAC DINH CAC CATION NHOM I (Ag+, Pb2+, Hg22+) MUC TIEU —Nam dugc ten, cong thirc thu6c thir nhom, thu6c thir cation —Vie't ducic phuang trinh ion NOI DUNG Thmic thir nhom Thu6c thir cUa cac cation nhOm I la acid hydrochloric n6ng d6 2N (HC1 2N) Khi tac dung vâi to cac ke't tüa trang, cac ke't dm c6 tinh chit khac amoni hydroxyd (NH40H) Phtrang trinh ion: Ag+ + Cr AgC11, - AgC1 tan dung dich NH4OH: AgC1 + NH4OH —> [AYNI-13)2]Cl + 2H20 Pb2+ + 2cr - PbC12 kh6ng tan dung dich NH40H Hg22+ + 201 —>Hg2c124, - Hg2C12 h6a den dung dich NH4OH: Hg2C12 + 2N1140H —> (NH2Hg2)C1 + NH4C1 + 2H20 (NH2Hg2)C1 —> [NH2Hg]Cl + Hg tüa mau den Thaw 64 cation 2.1 Thaw thir dm ion Ag+ • Kalicromat (K2Cr 04) 2Ag+ + Cr042- —> Ag2Cr044, dm tham Phan img tay theo m6i tnrong ma thu dugc cac san phAm khac Jai lieu on thi tuyen sinh mon: floa Phan Tich Trirenig Dgi hpc Tra Vinh • Kali iodid (KI) Agb i, Ag+ + tua Vang nhat Neu sir dimg KBr, phan img ding to ket tUa mau yang: Ag+ + Br- —* AgBni, Ma yang nhat Nhung AgI se khong tan acid va NH4OH dc AgBr kh6ng tan cac acid nhung tan NH4OH • Natricarbonat (Na2CO3) 2Ag+ + C032- —> Ag2C034, Ma yang nhat 2.2 Thutie thir eiia ion Pb2+ • Amoni sulfua [(NH4)2SI boric H2S (1\11-14)2S —> PbSsi, Ma den pb2+ pb2+ + H2S + 2N1-14+ PbS4, Ma den + 2H+ PbS khong tan HC1, H2SO4 nhung tan HNO3 loan, nOng holac HNO3 3PbS + 8HNO3 wan —> 3Pb2+ + 6NO3- + 2N0 + 3S + 4H20 3PbS + 8HNO3 loan —> 3PbSO4 + 8N0 + 41-120 • Kali iodid (KI) Pb2+ + 211 —> PbI24 Ma yang Tim yang tan nuac ming, d nguOi lai ket tOa tinh th'e mau yang Ong anh • Kalicromat (K2Cra4) Pb2+ + Cr042- —> PbCr044, Ma yang turn Tim yang tan dung dich acid nitric, dung dich natri hydroxyd, khong tan acid acetic • Acid sufuric Mang (H2SO4) Pb2+ + S042- —> PbS044, tUa trang Cac cation Ag+ va Hg22+ chi tao dugc ket tüa voi S042- nZing dO cOa chimg tuang di lan • Natricarbonat (Na2CO3) Pb2+ + C032- —> PbCO3 4, Ma tang Tai lieu on thi tuyen sinh mon: I-16a Phan Tich Tru&ng Dgi h9c Tra Vinh 2.3 Thu& thfr ctia ion lig22+ • Amoni hydroxyd (NH4OH) Tao ket tüa xam den (Hg° nguyen tei) 2Hg2(NO3)2 + 4NH3 + H20 —> (NH2Hg20)N113,1, trang+2Hgle den + 3NH4NO3 • Kalicromat (K2Cra4) Hg22+ + Cr042- —> Hg2Cra4sle dm gach • Kali iodid (KV Hg22+ + 21- —> Hg2I24, ma mau xanh Tim nu cho thuOc thil• KI du thi se chuyen sang mau den (Hg° nguyen to) Hg2I2 + 2KI > Hg°1, mau den + K2[Hg2I4] • Natricarbonat (Na2CO3) Tao ket tüa xam den (Hgo nguyen to) Hg22+ + C032- —> Hg2CO3 Hg2CO3 —> Hg04, + Hg +CO2 So d xfic dinh cation nhom I DD g6c + HC1 2N có (Ma trAng) +NH4OH 1, den Tim Hg22+ Khong tan tan Tim Pb2+ • Tim Ag+ Tai lieu on thi tuyjn sinh mOn: I-16a Phan Tich Trteang Dgi hgc Tra Vinh Bai XAC DINH CATION NHOM II (Ba2+, Ca2+) MI.JC TIEU —Trinh bay duqc ten, ding thirc h6a hoc cila thuoc thir nh6m II, hien tuong dc tnrng cation nh6m II tac dung vai thuac thir nhom va vie't phucmg trinh ion de minh hoa —Ke ducyc ten deg thirc h6a hoc, hien tuqng dc tnrng cüa thuac thir xac dinh cation Ba2+, Ca2+ va viet phucmg trinh ion de minh hoa NO! DUNG Thu& thfr nhom Thuac thir dm cation nhom II la acid sufuric (H2SO4 2N) Cac cation nhOm II the dung voi thuac thir H2SO4 2N tao kat dm tang Trong phan Ung ion Ba2+ kh6ng can diau kin nao Ca2+ can mai truang aceton hoc ethanol 700 Phacrng trinh ion Ba2+ + S042- BaSO4 mau trang + S042- CaSO4 mau trang Ca Thu& thir cation 2.1 Thu& thii cation Ba2+ • Kalicromat (K2Cr04): ion Ba2+ tac dung vai thuac th* kali cromat tao kat tua mau yang tuai, tua khong tan NaOH 2N va CH3COOH Ba2+ + Cr042" —> BaCr04 yang tuoi • Phan t'e ng voler: kat dia ion Ba2+ cluOi clang mu& bani sulfat bang acid sulfuric mai tnreng thu6c tim (kali permanganat), tüa bani sulfat hap phu thuac tim nen Co mau hang Ba2+ S042- BaSO4 mau hang Sau dung nu& oxy gia (H202) mai tnr6ng acid sulfuric a khir mau tim hang dm dung dich, rieng tüa bani sulfat van ca mau hang 5H202 + 2K1VIn04 + 3H2SO4 Tai lieu on thi tuyen sinh mon: I-16a Phan Tich K2SO4 + 2MnSO4 + 502 + 8H2 Twang Dgi h9c Tra Vinh • Natricarbonat (Na2CO3) Ion Ba2+ tac dung vói Natricarbonat t5 ket tUa tang Ba2+ + C032" BaCO3 i tfia trang 2.2 Thaw tit& ctia ion Calf • Amoni oxalat 1(NH4)2C2041: ion Ca' tac dung vai thu6c thir amoni oxalat tao ket tUa tang Ca' (1•11-14)2C204 —> CaC204 L + 2M-14+ Ion Ba2+ ding cho ket qua tuang AT, do de tranh nham Ian can tin hanh xac dinh ion Ba2+ tnroc Cac ket tUa CaC204 va BaC204 du tan HC1, HNO3; nhung CaC204 thi kh6ng tan CH3COOH c6n BaC204 thi tan • Natricarbonat (Na2CO3) Ion Ca2+ tac dung vai thu6c thu• natri carbonat tap ket tUa tang Ca2+ + C032- —> CaCO3 1, dm trang Su d xfic dinh cation nhelm I, nhom II tan DD gec + HC1 trang + NH4OH Tim Ag+ Kh6ng4an Tim Pb2+ Khong tüa • Tüa trang Tim Ba2+ KhongtU + ethanol 70° Tim tang Tim Ca' DD gee + H2SO4 Tai lieu on thi tuyen sinh mon: Hoa Phan Tich Trufmg Dgi h9c Tra Vinh Bai XAC DINA CATION NHOM III (Zn2+, MiJC TIEU — Trinh bay duvc ten, c6ng tilde h6a h9c cUa,thu6c thir nhom, hien tucyng d'ac trung cation nhOm III tac dung vai thu6c thir nh6m va viet phuong trinh ion de minh hoa —Ke ten ding thdc hem h9c, hien tugng d'ac trung cda thuoc thir xac dinh NOI DUNG Thaw thir nhorn ThuiSc thir nhOm oh cation nhom III la NaOH 2N Cac cation nhOm III tac dijng \Ted thu6c thir NaOH tap ket tüa tang, la cac hydroxyd lu'ang tinh Khi cho dix NaOH 2N thi cac ket tUa dO hoa tan vi chimg the hien tinh acid, tan kiem Phtrang trinh ion Zn2+ + 20H" —> Zn(OH)2 AO+ + 30H" si Al(OH)3 Khi cho dix NaOH 2N Zn(OH)2 + 2011" Zn022" + 2H20 Al(OH)3 + Off —> A102" + 2H20 Thaw tit& cation 2.1 Thaw thir ion Zn2+ • Montecqui: moi twang acid acetic, ion Zn2+ tac diving vài thuoc thd Montecqui A va Montecqui B to ket tüa mau tim sim • Amoni sulfur hay hydro sulfur: ion Zn2+ tac dvng vai thutic thd tao ket tua tang, ket Ma tan dung dich HC1, kh6ng tan CH3COOH Zn2+ + H2 S ZnS1, + 2H+ Zn' + (NH4)2S —> ZnS.1, + 2NH4+ • Natri carbonat (Na2CO3) Ion Zn2+ tac ding vâi Na2CO3 tao ket tda tang Tai lieu on thi tuyen sinh mon: Hoa Phan Tich Triceing Dgi h9c Tra Vinh 2.2 Thmic thir ion A13+ • Aluminon (acid aurin trallikettYlic): ion A13+ tac dicing vâi thu6c thir aluminon to ke't tüa mau h6ng Phan img rat nhay, nhung ion Zn2+ ding cho k6t qua tuong tu, d tranh nham fan can xac dinh ion Zn2+ tru6c xac dinh ion Al3+ • Han h9p amoni hydroxyd + amoni chlorid: ion A13+ tac di,mg vâi On hop NH4OH + NH4C1 tao ke't tüa keo tang, dm tan NaOH, HC1, khong tan tong NH4C1: + 3NH4+ Al3+ + 3NH4OH > A1(OH)3 • Natri carbonat (Na2CO3): ion Al3+ tac dkulg vâi Na2CO3 cho k6t tim tang 2A13+ + 3C032" + 3H20 —> 2A1(OH)3 + 3CO21' Su 'Lac dinh cation nh6m I, nh6m II, nh6m III Tim Ag+ tan DD gOc + HC1 trang NH40H Khong th wn Tim Pb2+ Xam dgn Tim Hg22+ Khong tua Tfia trang Tim Ba2+ KbOng dia + ethanol 700 Tua tran Tim ca2+ DD gtic + H2SO4 Khong tfia DD g6c + NaOH du r Tniac Tim Zn2+ Sau Tim Al3+ Tim tang ri5i tan Tai lieu on thi tuyen sinh mOn: Ma Phan Tich TrIcong Dgi hoc Trg Vinh Bai xAc DINH' ATIoN NHOM V (Mg2+, Cu2+, Hg2) MiJC TIEU - Trinh bay ducyc ten, ding duly hoa h9c dm TT nhom, hin tucmg dac Wang cho cation nhom V tac ding voi TT nhOm va viet phuang trinh phan img caa Mg2+ de minh h9a - Ke &rye ten, ding thirc hoa h9c, hin tuyng dc tnxng dm TT xac dinh ion Cu2+, Hg2+, Mg2+ va viet phucmg trinh ion de mirth h9a NOI DUNG Thu& thir nh6m Thu'6c thir cilia cation nh6m V ding nhu thu6c thir nhOm cila cation nh6m IV la amoni hydroxyd cho du, voi sr c6 mitt cüa nu& oxy gia (H202) \TA amoni chlorid (N1140) Cac cation nhom V tac diving vai hO'n hop NH4OH + H202 + NH4C1 khong tao tüa vi: Mg2+ + 2NH4OH ± Mg(OH)2 + 2NH4+ Tüa Mg2+ Ma tan mOi twang ral4+ (NH4C1), can Cu2+, Hg2+ thi tao cac phirc chit tan Amoni chlorid (NH4C1) c6 vai tre tang n6ng d6 NH4+ a cac cation nhOm V kh6ng tao ket tUa, plain bit &roc v6i cation nhOm IV, nuOc oxy gia c6 vai tro d6i yeti nhom IV Thutic thii cation 2.1 ThuOc thir ion Cu2+ • Voi Amoni hydroxyd:t4o ket tUa mau xanh la, dm tan cho du NH4OH, tap phirc chit mau xanh lam Cu2+ + 4NH4OH —> [Cu(NH3)4]2+ (phirc chk mau xanh lam) + 4H20 • Voi Kali ferrocyanid: cho ket tüa mau d6 thArn 2Cu2+ + [Fe(CN)6]4- Cu2[Fe(CN)6] • Amoni sulfur hay hydrosulfur : tao ket tila den Cu2+ + H2S —> CuSsl, + 2H+ Cu2+ + (NH4)2S —> CuS + 2NH4+ Tai lieu on thi tuyen sinh mon: Ma Phan Tich Trtrang Dgi hQc Tra Vinh 2.2 Thu& thir ion Hg2+ • Voi KI: cho kêt dm do, tila tan cho du KI, t4o dung dich khemg mau Hg2+ 21" —> HgI2 mau HgI2 + 2KI —> K2[Hg14] khong mau • Natri hydroxyd: ion Hg2+ tac citing yOi NaOH cho ket lila yang Hg2+,+ 20H" —> Hg0li mau yang + H20 • Natri carbonat: cho ket dm nau hay yang nau 2.3 Thmic thii ion Mg2+ • Phan fing Igo muoi ke'p: Ion Mg2+ phan irng vâi hein h9p NH4OH + Na2HPO4 + NH4CI cho ket tüa trang (muoi kep magnesi amoni phosphat) NH4OH + Na2HPO4 —> MgNH4P044, + 2Na+, + H20 • Natri hydroxyd : Ion Mg2+ phan Ung vai NaOH 2N cho ke't tia trang, tila khong tan NaOH du Mg2+ + 20H —* Mg(OH)2,1r • Natri carbonat: Ion Mg2+ phan Ung yoi Na2CO3 cho ke't tüa trang Mg2+ + C032" —> MgC034, Su xac dinh cation nhom I, II, III, IV, V dung dich gOc 4, Den Tim Hg22+ Xanh — nau DD g6c + Na2CO3 • Tim Fe2+ tang va co I • Tim Bi3+ trang • DD go'c + HC1 2N trang + NH4OH tan Tim Ag+ Khong tan Tim pb2+ Khong Ma I trang • Tim Ba2+ • + ethanol 70° Tim tang DD g.tic + H2SO4 Khong Tim Ca2+ Kh8ng tua DD go'c + NaOH du Truck Sau Tai lieu on thi tuyen sinh mon: Hoa Phan Tich Tim Zn2+ Tim Al3+ 10