Thiết kế bài giảng hóa học 12 (tập 2) phần 1

CAO C U GlAC (Chii bien) Thiet kebdi gidng H6A HOC 12 TAP HAI ffi N H A XUAT BAN HA N0I TS CAO CU G I A C (Chu bien) - ThS HO THANH THUY *ã _r e% -ô THIET KE BAI GIANG m TflTP HW NHA XUAT BAN HA NOI Chirong DAI ClTOfNG VE KIM LOAI Bai 17 V! TRI CUA KIM LOAI TRONG B A N G T U A N H O A N V A C A U T A O C U A KIM LOAI A MUC TIEU BAI HOC Kiln thii'c HS biit: • Vi tri cua kim loai bang tuan hoan • Cau tao cua nguyen tu kim loai va cau tao tinh the ciia kim loai • Lien ket kim loai HS hieu: Mot so kieu cau true tinh the kim loai (mang tinh the luc phucmg, lap phuang tam dien, lap phuang tam khoi) KT nang • Suy dien: Tu vi trf cua kim loai suy cau tao va tinh chat • So sanh: Lien ket kim loai vai cac loai lien ket khac Tinh cam, thai dp Vai tro kim loai cuoc s6ng, bao ve va khai thac hop li tai nguyen, khoang san cua dat nuac B C H U A N B! C U A GV VA HS • GV: - Bang tuan hoan cac nguyen to hoa hoc - Bang phu ve so cau tao va ghi ban kinh cua nguyen tu cua cac nguyen to thuoc chu ki - Tranh ve kieu mang tinh thi cua kim loai » HS: - Xem truac noi dung bai hoc - Tap lam mot so mo hinh ve tinh thi kim loai C TI^N TRINH DAY - HOC Hogt dgng cua GV Hogt dong ciia HS Hogt dgng I VI TRI CUA KIM LOAI TRONG BANG TUAN HOAN GV chieu bang tuan hoan co to mau cac kl hieu nguyen to len man hinh (hoac treo bang tuan hoan len bang) cho HS thao luan GV huang dan HS tim vi tri cua kim loai bang: - Kim loai la cac nguyen to dugc to mau vang a bang tuan hoan - Phi kim la cac nguyen to dugc to mau tim a bang tuan hoan Yeu cau HS xac dinh vi tri cua kim HS quan sat thao luan cho ket qua: loai Vi tri kim loai gom: - Nhom IA din VIA (Nhom IA tru H nhom IIIA tru B) va mot phan nhom IVA,VA, VIA -NhomlBdInVIIIB - Hai ho Lantan va Actini GV bd sung: Ngoai each xac dinh a tren thi kim loai nam a: - Khoi nguyen to s (trir H, He) - Mot so a khoi nguyen to p - Toan bo khoi nguyen to d, f GV yeu cau HS riit ket luan ve vi tri ciia kim loai HS thao luan cho ket qua: Hogt dgng cda HS Hogt dgng cua GV - Kim loai chiem da so vi tri bang tuan hoan - Kim loai nam a phia dual ben trai cua bang tuan hoan II CAU TAO CUA KIM LOAI Hogt dgng I Cau tao nguyen tu" GV: Yeu cau HS viet cau hinh HS viet cau hinh ciia cac nhom electron nguyen tu ciia cac nguyen to - Kim loai: kim loai nNa, ^Mg, 13AI, 26Fe va iiNa: Is 2s 2p 3s cac nguyen to phi kim jjP jgS, 17CI i2Mg: Is 2s 2p 3s*' nAl: ls"2s 2p 3s 3p 26Fe: ls''2s 2p 3s 3p 3d 4s - Phi kim: 15P: Is 2s 2p 3s 3p igS: Is 2s 2p 3s 3p 17CI: ls"2s 2p 3s 3p GV: So sanh so electron a lop ngoai So electron a Idp ngoai ciing cua kim loai Cling cua cac nguyen tii kim loai, phi tii 1-3 electron phi kim thi thuang co kim tren va riit ket luan nhieu electron (tir 4-^7 electron tru H va hiem) Ket luan: Nguyen tir ciia hau hit cdc nguyen td kim logi deu cd it electron a GV diing bang phu ve sa cau tao va ghi ban kinh ciia nguyen tii thuoc chu ki (ban kinh nguyen tii dugc bilu dien bang nanomet, nm): lap ngodi cung (1-3 electron) Hogt dgng cua GV llNa i2Mg 13AI u S i ]5P Hogt dgng cda HS 16S 17CI 0.157 0,136 0,125 0,117 0,110 0,104 0,099 Yeu cau HS riit nhan xet ve su bien HS quan sat cac so lieu va nhan xet: thien ciia dien tich hat nhan va ban Trong cung chu ki, nguyen tic ciia nguyen kinh nguyen tu to kim logi cd bdn kinh nguyen tic lan han vd dien tich hat nhdn nhd han so vai nguyen tic cita nguyen to phi kim Hogt dgng Cau tao tinh the GV nhic lai mgt s6 kilu tinh thi da I HS nghien cuu SGK va len bang ve lai hgc a lap 10 Sau HS nghien ciiu cau triic tinh the kim loai SGK ve noi dung cau tao tinh the kim a) Mang tinh thi luc phwffng loai Yeu cau HS: - Neu cau triic cac loai tinh the (mo ta hinh ve) - Nhan xet ve dac kbit cua mang - Cac nguyen tii, ion kim loai nam tren tinh the kim loai cac dinh va tam cac mat cua hinh luc giac - Lay vi du mgt so kim loai diing va nguyen tu, ion nam phia - So sanh cac loai tinh the kim loai ciia hinh luc giac - Nguyen tii va ion chiem 74% lai 26% la khong gian - Vidu: Be, Mg, Zn, b) Mang tinh thi lap phirffng tam dien Hogt dgng cua HS Hogt dgng cda GV - Cac nguyen tu, ion kim loai nam tren cac dinh va tam cac mat cua hinh lap phuang - Nguyen tu va ion chiem 74% lai 26% la khong gian - Vidti: Cu, Ag, Au, Al, c) Mang tinh thi lap phutfng tdm khdi - Cac nguyen tu, ion kim loai nam tren cac dinh va tam ciia hinh lap phuang - Nguyen tu va ion chiem 68% lai 32% la khong gian -Fz't/w.-Li,Na,K,V,Mo, GV giai thieu: Trong tinh the kim logi, nguyen tu vd ion kim logi ndm a nhiing nut mang tinh the Cdc electron hod tri lien kit yeu vai hat nhdn nen de tach khdi nguyen tic vd chuyin dgng tu mang tinh thi Hogt dgng Lien ket kim loai GV: Dua tren c4u tao mang tinh the kim loai, phan tich, dien giang kien thiic lien ket kim loai Cl trang thai long va ran, cac nguyen tii kim loai lien ket vai bang mgt Hogt dgng cua GV Hogt dgng cua HS kieu lien ket hoa hgc rieng ggi la lien kit kim logi GV yeu cau HS nghien ciiii SGK va neu khai niem lien ket kim loai HS nghien ciiu SGK va nhan xet: - Lien ket kim loai la lien ket dugc hinh giQa cac nguyen tii va ion kim loai mang tinh the su tham gia ciia De kliac sau kien thiic ve lien ket kim cac electron tu loai vai cac lien ket khac GV yeu cau HS thao luan cho ket qua HS so sanh: - Lien ket kim loai vai lien ket cong + Lien ket kim logi v&i lien kit cong hoa tri hod tri Gidng nhau: Deu co su gop chung, diing chung electron Khdc nhau: - Lien ket cong hoa tri chi gop chung mgt so cap electron - Lien ket kim loai gop chung hau het cac electron tu cua nguyen tir kim loai - Lien ket kim loai vai lien ket ion + Lien kit kim logi v&i lien kit ion Giong nhau: Deu co ban chat la lire hut tinh dien giira ion duang vai phan tir mang dien tich am Khdc nhau: - Lien ket ion la luc hut tmh dien giiia ion am vai ion duong - Lien ket kim loai la luc hut tmh dien giira electron vai ion kim loai Hogt dgng cua HS Hogt dgng cua GV Hogt dgng CUNG CO B A I V A B A I T A P V E N H A GV chieu cac bai tap sau len man HS quan sat theo luan cho ket qua hinh cho HS thao luan ciing c6 noi dung bai hgc: Bai Lien ket kim loai la lien ket Dap an A dugc hinh do: A Su gop chung electron hoa tri ciia cac nguyen tir kim loai B Cac electron tu kim loai phan xa tot nhiing tia sang tai C Do su gop chung mgt so cap electron hoa tri D Sir gop chung toan bg electron cua cac nguyen tir kim loai Bai Cho cac nguyen to co so hieu Dap an C nguyen tir la 12, 17, 1, 26, 24, 9, 7, 15 So nguyen tir la kim loai la A 12, 17, 1.26,24 B 17, 1,9,7, 15 C.12, 26, 24, D 12,26,24, 7, 15 Bai tap ve nha: 1, 2, 3, 4, 5, 6, 7, 8, (SGK) D HU-aNG DAN GIAI BAI TAP TRONG SGK Chgn dap an B Chgn dap an D Chgn dap an B Chgn dap an C nNaOH = 0,03.1 =0,03 (mol) n^^so, = 0,15.0,5 = 0,075(mol) Phuang trinh hoa hgc: M + H2SO4 + H2SO4 -^ MSO4 + H2 (1) 2NaOH -^ Na2S04 + 2H2O (2) 0,015(mol) ACI2 Fe + ACI2 -^ FeCb + A Taco: A-56 — X = 0,8 => x 0,8 A-56 Theo bai ra, ndng FeCl2 dung dich la 0,25M nen so mol FeC^ la 0,25.0,4 = 0,1 (mol) -^ - ^ ^ = 0,1 => A = 64 (Cu) A-56 ^cn=T^cua, = - ^ = 0,2(mol) 0,2 Nong cua muoi B (CUCI2) dung dich C la = 0,5(M) 0,4 10 Hogt dgng cua GV Hogt dgng cua HS B Na2C03 C.NaHC03vaNa2C03 D Na2C03 va NaOH Cau Cho cac dung dich cd cimg Cau Chgn dap an B nIng mol/ lit: (1) NaOH, (2) Ba(0H)2, (3) NH3 pH cac dung dich dugc xep theo thii tu giam dan la A (1)(2)(3) B.(2)(l)(3) C.(3)(2)(l) D.(2)(3) (1) Cau Cho kim loai X vao dung dich Cau Chgn dap an B (NH4)2S04 du, sau phan irng tao mgt chat ran khdng tan va cd thoat Vay X la A Na B Ba C Fe D Mg Cau Hoa tan m gam hdn hgp Cau Chgn dap an B Na2C03 va KHCO3 vao nude de dugc 400 ml dung dich A Cho tir tir 150 ml dung dich HCl IM vao dung dich A, thu dugc dung dich B va 1,008 lit (dktc) Cho B tac dung vdi Ba(0H)2 du, thu dugc 29,55 gam ket tua Gia tri ciia m la A 10,60 g B 20,13 g C 11,13 g D 13,20 g Hogt dgng BAI TAP VE NHA GV yeu cau HS ve nha lam them cac bai tap sau 148 Ngudi ta giai thich nhu the nao su bien doi khong deu dan ciia khdi lugng rieng, nhiet soi va nhiet nong chay cua cac kim loai nhom IIA bang tuan hoan? Hay giai thich trinh tu sip xIp khac cua kim loai kiem d day dien the va d bang tuan hoan Mdt don chat A nhe mau trang bac, dan nhiet va dien tot, phan ling vdi nude dun nong tao nen hai chat: mgt don chat va hgp chat B Chit B phan ung vdi axit C tao nen mudi Dung dich cua muoi dugc them bari clorua tao nen ket tiia trang khdng tan axit va kiem Hoi A, B va C la chit gi? Viet phuang trinh cua cac phan img Khi tac dung vdi nude 6,0g kim loai giai phong 3,361it hidro (dktc) Xac dinh kim loai dd, cho biet nd c6 boa tri bai cac hgp chat Khi dien phan 13,4g mgt chat ndng chay, d anot thoat l,12lit hidro (dktc) Xac dinh chat dd Dun nong 6,2g oxit kim loai kiem quyen luu huynh (IV) oxit, thu dugc 12,6g mudi Xac dinh phan ciia mudi Muon boa tan 6g oxit cua kim loai boa tri hai, can dung 60g axit sunfuric 24,5% Xac dinh cdng thiic cua oxit Mgt lugng du cacbonic tac dung vdi 8,7g mgt hgp chat chua biet cua kim loai vdi oxi tao nen chat ran A va giai phdng B Hoa tan chat A vao nude, them mdt lugng du dung dich bari nitrat, thu dugc 9,85g ket tiia Cho B di qua dng dung ddng nung ndng, khdi lugng ciia ong tang them 4,00 g Xac dinh cong thiic ciia hgp chat chua biet Viet phuong trinh ciia phan ung giira oxit cua cac nguyen to nhdm II vdi oxit ciia cac nguyen td chu ki 10 Tai khong the dap tat magie chay bang binh ciiu boa chiia cacbonic? 11 Viet phuang trinh cua phan ung cho phep thuc hien nhirng bien boa sau: LiCI -> Li -^ Li3N -> LiOH -> LiHS03 12 Co hon hgp cua canxi, canxi oxit va canxi cacbua vdi ti le moi 1:3:4 tuong ling Tim the tich nude cd the phan ling vdi 35g hon hgp 149 13 Khi phan buy hoan toan nitrat kim loai kiem, thu dugc cac san pham co khdi lugng bang 78,26%) khdi lugng ban diu cua nitrat Xac dinh cdng thiic cua nitrat 14 Mgt hon hgp cd phin khdi lugng nhu cua hidrua va photphua ciia kim loai kiem tac dung vdi nude tao nen hon hgp cd ti khoi so vdi he li la 2,2 Xac dinh kim loai d cac hgp chit ban diu TiNH CHAT Bai 29 LUYEN TAP CUA NHOM VA HQP CHAT COA NHOM A MUC TIEU BAI HOC Kiln thiPC • Cung cd, he thong hoa kien thiic ve nhdm va hgp chit cua nhdm • So sanh tinh chat ciia nhdm vdi kim loai kilm, kim loai kilm thi KT nang • Ren luyen kT nang giai bai tap tinh toan vl nhdm va hgp chat nhdm • Ren luyen ki nang nhan bilt ion nhom B C H U A N Bj CUA GV VA HS • GV: He thong cau hdi bai tap phii hgp • HS: On tap bai nhom va hgp chat nhom Xem trudc ndi dung bai luyen tap C TI^N TRiNH DAY- HOC Hogt dgng cua GV Hogt dgng cda HS I KIEN THirC C A N NHOf Hogt dgng 1 Nhom GV yeu cau HS neu: HS thao luan va nhan xet - Cau hinh cua nhdm tir dd suy vi a) Cdu hlnh, v/ tri cua nhom tri cua Al bang tuan hoan - ciu hinh: Is 2s 2p 3s 3p 150 Hogt dgng cua HS Hogt dgng cda GV - Nhom nam d vi tri: Chu ki nhom IIIA cua bang tuan hoan Tinh chat vat li ca ban- ciia nhdm b) Tinh chdt vdt li: Nhom la kim loai nhe ~ (d=2,7gam/cm ) dan dien, dan nhiet tot va deo - Tinh chat boa hgc(viet phuong c) Tinh chdt hod hoc Nhom cd tinh khir trinh boa hgc minh hoa) manh: Al ^^ Al + 3e nhung kem kim loai kiem va kim loai kiem tho - Tac dung vdi phi kim 4A1 + 3O2 ^ ^ 2AI2O3 Ldp oxit nhom rat ben nen d thuc te nhdm khdng tac dung vdi oxi d nhiet thudng - Tac dung vdi axit 2A1 + 6HC1 -> 2AICI3 + 3H2 - Tac dung vdi oxit kim loai yeu 2A1 + Fe203 -^-^ 2Fe + AI2O3 - Tac dung vdi nude 2A1 + 6H2O > 2A1(0H)3 + 3H2 -Tac dung vdi dung dich baza manh 2AI + 2NaOH +2H2O ^2Na[Al(OH)4] + 3H2 Hogt dgng 2 Hop chat nhom GV chia HS nhdm td chiic HS cac nhom thao luan lan lugt cho ket cho HS thao luan cac van dl sau day qua 151 Hogt dgng cda GV Nhdm Neu tinh chat ciia nhdm oxit Hogt dgng cda HS a) Nhom oxit (Nhdm 1) Nhdm oxit (AI2O3) la oxit luong tinh: vira tan dung dich axit manh, vira tan dung dich kilm manh - AI2O3 tac dung vdi dung dich axit manh AI2O3 +6HCI ^2A1C13 +3H2O - AI2O3 tac dung vdi dung dich bazo manh Al203+2NaOH ^2Na[Al(OH)4] + H2O natri aluminat Nhdm2 hidroxit Neu tinh chat cua nhdm b) Nhom hidroxit (Nhom 2) Nhom hidroxit (A1(0H)3) la, hidroxit ludng tinh, vira tan dung dich axit manh, vira tan dung dich kilm manh - Tac dung vdi dung dich kilm manh Al(OH)3+NaOH -> Na[Al(OH)4]+2H20 - Tac dung vdi dung dich axit manh A1(0H)3 + 3HC1 -^ AICI3 + 3H2O Kit ludn: A1(0H)3 la hidroxit ludng tinh Nhdm Neu cdng thiic va ling dung c) Phen nhom (Nhdm 3) cua phen nhdm Phen chua: K2S04.Al2(S04)3.24H20 Phen nhdm: M2S04.Al2(S04)3.24H20 (M^laNa^;Li^NH4'") - Phen nhdm cd tinh axit dugc img dung lam nude due va lam chit cim mau cdng nghiep 152 Hogt dgng cua HS Hogt dgng cda GV Nhdm neu phuang phap nhan biet d) Phuang phdp nhgn biit At (nhdm 4) ion Al - De nhan biet ion Al ta diing dung dich GV nhan xet ket qua cua timg nhom NaOH loang de cac nhom cdn lai riit kinh nghiem - Phuong trinh boa hgc va kien thirc ca ban can nhd Al^^ + 30H~ -> A1(0H)3^ A1(0H)3 + OH" -^ [A1(0H)4]" (tan) II B A I TAP Hogt dgng GV Chieu cac bai tap SGK len HS thao luan cho ket qua man hinh cho HS thao luan Cau Nhdm ben mdi trudng Cau Chgn dap an B khong va nude la A Nhom la kim loai kem boat dgng B Cd mang oxit AI2O3 ben vung bao ve C Co mang hidroxit A1(0H)3 ben viing bao ve D Nhom CO tinh thu dgng vdi khong va nude Cau Nhom khong tan dung dich nao sau day? A HCl B H2SO4 C NaHS04 D NH3 Cau Chgn dap an D Cau Cho 31,2 g hdn hgp bdt Al va Cau Chgn dap an B AI2O3 tac dung vdi dung dich NaOH 13,44 UH =—— = 0,6(mol) du thu dugc 13,44 lit H2 d dktc "^ 22,4 Khoi lugng timg chat hdn hgp Phuong trinh hoa hgc: 153 Hogt dgng cua GV ban dau lan lugt la Hogt dgng cda HS 2A1 +2NaOH +2H2O -^2NaA102 +3H2 A 16,2 gam va 15 gam 0,4 mol B 10,8 gam va 20,4 gam AI2O3 + 2NaOH ^2NaA102 +H2O C 6,4 gam va 24,8 gam D 11,2 gam va 20 gam Cau H§n hgp X gdm hai kim loai K va Al CO khIi lugng 10,5g Hoa tan hoan toan hon hgp X nude dugc dung dich A Them tir tir dung dich HCl IM vao dung dich A: liic diu khong c6 ket tua, them dugc 100ml dung dich HCl IM thi bit diu cd kit tua Tinh phan % sd mol cua cac kim loai X < 0,6(mol) mAi = 27.0,4 = 10,8 (gam) m^,^o^ =31,2-10,8=20,4(gam) Cau Phuong trinh hoa hgc: 2K + 2H2O ^ 2K0H + H2 X mol (1) X mol 2A1 +2KOH+2H20-^2KA102 +3H2(2) y mol y mol Do X tan hit nen Al tan hit, KOH du sau phan ung (2) Khi them HCl, ban diu chua cd ket tua vi: HCl + KOHdu -> KCl + H2O X mol (3) X mol Khi HCl trung boa hit KOH du thi bit dau cd ket tua KAIO2+HCI +H2O ^ A1(0H)3 i + KCl Vay dl trung boa KOH du cin 100 ml dung dich HCl IM riHCl = "KOH sau pir (2) = O J - = O'l ("loO Ta cd he 'x-y = 0,l [x = 0,2 l39x + 27y = 10,5 [y = 0,l %n^ = — 100% = 66,67% " 0,3 %nAi = 100% - 66,67% = 33,33% 154 Hogt dgng cua GV Hogt dgng cua HS GV cho HS lam them cac bai tap sau Cau Liy V lit dung dich NaOH Cau Chgn dap an B 0,4M cho vao dung dich cd chiia 58,14gAl2(S04)3 thu dugc 23,4g kit tua Gia tri V la A 2,25lit hay 2,681it B 2,65lit hay 2,251it C 2,651it hay 2,851it D 2,55 lit hay 2,98 lit Cau Qua trinh san xuat nhdm Cau Chgn dap an D trongedng nghiep, thoat la A O2 B Hon hgp CO2, CO C Hdn hgp O2, N2 D H6n hgp CO2, CO, O2 Cau Hoa tan 0,54 gam Al 0,5 lit dung dich H2SO4 0,1M thu dugc dung dich A Them V lit dung dich NaOH 0,1 M cho din kit tiia tan trd lai mgt phan Nung ket tua thu dugc den khdi lugng khdng dii ta dugc chat ran nang 0,51 gam V cd gia tri la A 1,1 lit B 0,7 lit C 0,3 lit D 1,2 lit Cau Chgn dap an A Cau Cho a mol NaA102 tac dung Cau Chgn dap an A vdi dung dich cd chiia b mol HCl Vdi dieu kien nao cua a va b thi xuit hien ket tua? 155 Hogt dgng cua GV Hogt dgng cua HS A b < 4a B b = 4a C b > 4a D b > a Cau Mgt dung dich cd chira Cau Chgn dap an B cation la Fe^^ 0,1 mol, Al^^ 0,2 mol — 2— va anion la Cl x mol, SO4 y mol Biet rang cd can dung dich thu dugc 46,9 gam chat ran khan Tdng sd mol cua anion la A 0,4 B 0,5 C 0,6 D 0,7 Hogt dgng BAI TAP VE NHA GV yeu cau HS ve nha lam them cac bai tap sau Cau 4.(SGK) Chi dimg them mgt boa chit, hay phan biet cac chit nhiing day sau va viet phuang trinh boa hgc cua phan ling dl giai thich a) Al, Mg, Ca, Na b) Cac dung dich NaCl, CaCl2, AICI3 c) Cac chit bgt CaO, MgO, AI2O3 Cau (SGK) Viet phuong trinh boa hgc de giai thich cac hien tugng xay khi: a) Cho dung dich NH3 du vao dung dich AICI3 b) Cho tir tir dung dich NaOH din du vao dung dich AICI3 c) Cho tir tir dung dich Al2(S04)3 vao dung dich NaOH va ngugc lai d) Sue tir tir CO2 vao dung dich NaA102 e) Cho tir tir din du dung dich HCl vao dung dich NaA102 156 Bai 30 BAI THU'C HANH TINH CHAT CUA NATRI, MAGIE, NHOM VA HOP CHAT CUA CHUNG A IViyC TIEU BAI HOC KiĐn thii'c ã Ciing CO he thdng tinh chat boa hgc dac tnmg cua natri, magie, nhdm va hgp chat quan trgng cua chiing • Giup HS biet each tien hanh mgt sd thi nghiem: - So sanh phan ling cua Na, Mg, Al vdi nude - Al tac dung vdi dung dich kiem - A1(0H)3 tac dung vdi dung dich NaOH, H2SO4 loang KT nang • Ren luyen tinh than trgng chinh xac tiln hanh thi nghiem • Sir dung dung cu boa chit de tien hanh dugc an toan, cdng cac thi nghiem • Ren luyen kT nang quan sat, neu va giai thich hien tugng • Viet tudng trinh thi nghiem Tinh cam, thai Thong qua boat ddng thi nghiem tao nen hiing thii hgc bg mdn boa hgc B C H U A N Bj CUA GV VA HS • GV - May tinh, may chieu, cac phieu hgc tap - Hoa chat: +Kim loai: Na, Mg, Al + Dung dich: NaOH, AICI3, NH3, HCl - Dung cu: + Ong nghiem, den cin + Cdc thuy tinh + Bg gia thi nghiem • HS: Xem trudc bai thue hanh 157 C TI^N TRiNH DAY- HOC Hogt dgng cua GV Hogt dgng cua HS Hogt dgng I DAN DO TRl/OC BUOI THLTC H A N H GV neu cac ndi dung chinh ciia buli HS nghe GV trinh bay va thao luan theo thuc hanh nhom thuc hanh - GV yeu cau HS trinh bay cac y kiln lien quan den buoi thuc hanh - Luu y HS dung boa chit vira dii va sir dung can than cac dung cu thi nghiem - Chia ldp hgc cac nhom thuc hanh mli nhom gIm 4-5 HS I NOI DUNG THI NGHIEM VA CACH TIEN HANH Hogt dgng THI NGHIEM I SO S A N H K H A N A N G P H A N LTNG CUA Na, Mg Al VOl NLfOC GV cho HS nghien ciiu SGK va cho HS nghien ciiu SGK va len bang tiln HS len ban thi nghiem tiln hanh ba thi hanh thi nghiem: nghiem SGK HS 1: Rdt nude vao Ing nghiem thii nhit khoang 3/4 dng, them mdt it phenolphtalein roi bd vao dd mgt mau Na bang hat gao HS 2: Rot nude vao Ing nghiem thir khoang 5ml, them mgt it phenol phtalein roi bd vao dd mdt mau Mg Sau dun ndng dng nghiem HS 3: Rdt nude vao dng nghiem thii ba khoang 5ml, them mdt it phenol phtalein rdi bd vao mgt miu Al Sau dun nong dng nghiem 158 Hogt dgng cua HS Hogt dorigcda GV HS quan sat cho nhan xet GV hudng dan HS quan sat va so sanh dng nghiem thif nhat: Thiy mau Na hien tugng d dng nghiem, giai thich phan ling manh vdi nude co thoat va viet phuang trinh boa hgc xay ta manh va dung dich chuyin sang mau hdng GV hudng dan HS giai thfch thi nghiem Gidi thich: Kim loai Na phan img manh vdi nude tao H2 va dung dich baza lam phenolphtalein hoa hing Phuang trinh hod hoc 2Na + H2O -> 2NaOH + H2T dng nghiem thii- hai: Thiy mau Mg phan ling cham vdi nude ed khf thoat Khi dun ndng thi phan img xay manh hon va dung dich chuyen sang mau hong nhat Gidi thich: Kim loai Mg phan ung cham vdi nude tao H2 va dung dich baza yeu lam phenolphtalein hdng nhat Phuang trinh hod hoc Mg + H2O -> Mg(0H)2 + H2t GV bo sung: Nlu pha bo ldp oxit dd Ong nghiem thu ba: Thay mau Al hau (hoac tao bin hdng Al-Hg), thi nhu khong cd hien tugng nhom se tac dung vdi nude d tihiet Gidi thich: Kim loai Al phan ling nude thudng tao ldp oxit ben ngan cho phan ling xay ke ca dun ndng Phuang trinh hod hoc 2A1 + 6H2O 2AI(OH)3 > 2A1(0H)3 + 3H2 -^ AI2O3 + 3H2O 159 Hogt dgng cua GV Hogt dgng cda HS Hogt dgng THI NGHIEM NHOM T A C DUNG vOl DUNG DICH KIEM GV lam thi nghiem: Rdt 2-3 ml NaOH vao ong nghiem va bd vao mgt mau nhom Sau dd dun ndng (de phan img xay nhanh ban) Yeu cau HS quan sat, neu hien tugng giai thich va viet phucmg trinh boa hgc HS quan sat va nhan xet: Hien tugng: Thiy mau nhdm tan dan ddng thdi cd thoat Gidi thich: Trong khdng nhdm bj oxi boa tao mdt Idp oxit mong ben ngoai bao ve nhom GV hudng dan HS giai thich (tranh - AI2O3 la oxit ludng tinh nen tac dung trudng hgp HS hieu nham nhdm la vdi dung dich kiem tao mudi tan kim loai ludng tinh) Al203+2NaOH + H ^ Na[Al(0H)4] Natri aluminat (tan) - Khi khong cdn mang oxit bao ve, nhdm se tac dung vdi nude tao AI(0H)3 va giai phdng H2 2AI + 6H2O > 2A1(0H)3 + 3H2 - A1(0H)3 la hidroxit luang tinh nen tac dung tiep vdi dung dich kiem A1(0H)3 +NaOH^Na[Al(OH)4] + H2O Cong (1) va (2) ta cd phuang trinh boa hgc sau: 2A1 +2NaOH +2H2O ^2Na[Al(OH)4] + 3H2 Kit ludn: Nhdm co the tan dung dich kiem va giai phdng hidro 160 Hogt dgng cua GV Hogt dgng cda HS Hogt dgng THI NGHIEM TINH CHAT LUONG TINH CUA A1(0H)3 GV cho HS nghien cim SGK yeu ciu HS nghien ciiu SGK va cho kit qua: - HS 1: chuan bi cac boa chit - HSl: Hod chdt: dung dich AICI3, dung - HS 2: Neu phuang phap va tiln dich NH3,dung dich H2SO4 loang, dung hanh thi nghiem dich NaOH - HS Neu hien tugng, giai thfch vilt Dung cu: ong nghiem, Ing hiit cap Ing phuang trinh boa hgc nghiem - HS neu kit luan - HS 2: Tien hanh thi nghiem Buac 1: Dilu cbl AI(0H)3 Rot vao ong nghiem 3ml dung dich AICI3 rdi nhd dung dich NH3 din du vao dng nghiem Buac 2: Thir tinh chit cua AI(0H)3 - Lay dng hiit nhd gigt biit dung dich NaOH vao vao Ing nghiem thii nhit thu dugc d budc ding thdi lie nhe - Lay ong hiit nho gigt hiit dung dich H2SO4 loang vao vao dng nghiem thir hai thu dugc d budc ddng thdi lie nhe HS 3: Hien tugng va phuong trinh boa hgc Budc 1: Thiy kit tua keo xuit hien co phuang trinh boa hgc sau Al^^ +3NH3+ 3H2O ^ Al(0H)3i +3NH; 161 Hogt dgng cua HS Buac 2: - Thay kit tiia keo tan din cd phan ung boa hgc sau AI(0H)3 +OH-^2[Al(OH)4]" + 2H2O - Thiy kit tua keo tan din cd phan ling boa hgc sau Al(OH)3 + 3H^ -^ Al^^ + 3H2O HS 4: Kit luan Al(OH)3 Id hidroxit luomg tinh Hogt dgng II CONG VIEC SAU BUOI THlTC H A N H GV nhan xet ve buoi thuc hanh va HS thu dgn, ve sinh phdng thi nghiem hudng dan HS thu dgn boa chit, rira can than, an toan dng nghiem va dung cu thi nghiem, ve sinh phdng thi nghiem GV yeu ciu HS lam tudng trinh theo HS lam tudng trinh theo mau sau day: mau: Ngay .thing nam Ho va ten: Lo-p: To thi nghiem: Tipdmg trinh hoa hoc bai s6: Ten bai: Ten thi nghiem 162 Phuongphap tiin hanh Hien tugng quan sit GUI thich - viit phuong trinh phin ung