CAO CU GlAc (Chu bien) NHA XUAT BAN HA NOI TS CAO C U G I A C (Chu bign) - ThS HO THANH THUY THIET KE BAI GIANG NflNQCflO-TilPHfll NHA XUAT BAN H A NOI ChiroTig DAI CirONG VE KIM LOAI Bai 19 KIM LOAI VA HQP KIM A MUC TIEU BAI HOC Kiln thiPc HS biit: • Vi tri cua kim loai bang tuan hoan • Cau tao ciia nguyen ttr Icim loai • Kliai niem, tinh chat va ung dung cua hop kim HS hiiu: • Nhirng tinh chat vat li va tinh chat hoa hpc cua kim loai, hop kim • Nguyen nhan gay tinh chSt vat li chung, tinh khu cua kim loai KT nang • Ren luyen kT nang: Tu vi tri cua kim loai suy cau tao va tinh chSt ã ã DĐn dugc nhiing phan ijng hoa hoc va thi nghiem hoa hoc chung minh cho nhirng tinh chat cua kim loai • Ren luyen kT nang giai bai tap ve kim loai Tinh cam, thai Biet dugc nhiing tinh chat quy gia cua kim loai lam cho HS co y thuc bao ve va su dung tiet kiem kim loai B C H U A N B! CUA GV VA HS • GV: - Bang tuan hoan cac nguyen to hoa hgc - Chuan bi mgt so thi nghiem minh hoa cho tinh khir ciia kim loai - Dung cu: Ong nghiem ca nho, ong nho gigt, den c6n, - Hoa chat: + Cac kim loai: Al, Cu Fe (dinh sit sach) + Cac dung djch: axit H2SO4 loang, H2SO4 dac, HNO3, CUSO4 • HS: Xem truac noi dung bai hgc C TI^N TRiNH DAY - HOC Hogt dpng ciia GV Hogt dpng cda HS A - KIM LOAI Hogt dpng I VI TRI CUA KIM LOAI TRONG BANG T U A N HOAN GV chieu bang tuan hoan len man hinh HS: Quan sat, thao luan cho ket qua: (hoac treo baag tuan hoan co to mau cac nguyen to len bang) cho HS quan sat Vi tri kim loai gom: GV huong dan HS tim vi tri ciia kim loai bang: - Nhom IA dgn VIA (Nhom IA trir H nhom IIIA tru B) va mgt phan nhom - Kim loai la cac nguyen to co to mau IVA,VA, VIA vang a bang tuan hoan - Nhom IB dSn VIIIB - Phi kim la cac nguyen to co to mau - Hai ho Lantan va Actini tim a bang tuan hoan Yeu cau HS xac dinh vi tri cua kim loai GV bo sung: Ngoai each xac dinh a tren thi kim loai nam a: - Khoi nguyen to s (trir H, He) - Mgt so a khoi nguyen to p HS thao luan cho ket qua: - Toan bg khoi nguyen to d, f - Kim loai chiem da so vi tri bang tuan hoan GV yeu cau HS nit ket luan ve vi tri ciia kim loai - Kim loai nam a phia duai ben trai ciia bang tuan hoan Hogt dpng cua HS Hogt dpng cua GV Hogt dpng II TINH C H A T VAT LI Tinh chat vat li chung GV giai thieu: dieu kien thuang cac HS lang nghe kim loai deu a trang thai ran (trir Hg), CO tinh deo, dan dien, dan nhiet va co anh kim Vay the nao la tinh deo, tinh dan dien, tinh dan nhiet, anh kim va tai kim loai CO cac tinh chat tren chung ta se nghien cuu timg tinh chat cu the a) Tinh deo GV yeu cau HS nghien cim SGK va cho biet: HS thao luan nhan xet va cho ket qua: - The nao la tinh deo? - Tinh deo ciia vdt lieu la tinh bi bien dang chiu ap luc ben ngoai hoac nhiet tac dung va van giu dugc trang thai bien dang thoi tac dung - Giai thich - Gidi thich: Kim loai co tinh deo la vi cac ion duang mang tinh the kim loai CO the trugt len de dang ma khong tach khoi nha nhiing electron tu chuyen dgng dinh ket chiing vai e.e;â âãâãâ e:â'â â:â.â ã: Electron tir đ : Ion duang kim loai â:ââ! iằj ã ã r r^.©.# Hogt dpng cua GV Hogt dpng cua HS GV bo sung: Kim loai c6 tinh deo Ion nhat la Ag sau la Al, Cu b) Tinh ddn diin GV yeu cau HS nghien cim SGK va cho biet: - The nao la tinh dan dien? Tinh ddn diin la tinh chit cua vat lieu gin vao diu vat lieu mgt hieu dien thg thi tao dong chuyen dai co huang cua electron tir cue am sang cue duang Gidi thich: Do kim loai co cac - Giai thich electron tir do, chuyen dgng tir mang tinh the, co hieu dien the lap tiic cac electron tu chuyen dgng GV bo sung: Kirn loai dan dien tot dong co huong tao dong dien nhat la Ag, sau den Cu, Au, Al, Fe c) Tinh ddn nhiet GV yeu cau HS nghien cuu SGK va cho biet: - Th6 nao la tinh din nhiet? Giai thich - Tinh ddn nhiet la tinh chat cua vat lieu CO th6 truy6n nang lugng (nhiet) tir vi tri den vi tri khac - Gidi thich: Do kim loai co mat cac electron tu mang tinh the Cac electron viing nhiet cao co dgng nang lan, chuyen dgng hon loan va nhanh chong sang viing co nhiet thap han, truyen nang lugng cho cac ion duang a viing nen nhiet lan truyen GV b6 sung: Thuang caic kim loai dan dugc tir viing den viing khac khdi kim loai dien tot cung dan nhiet tot Hogt dpng cua GV Hogt dpng cua HS d) Anh kim GV yeu ciu HS nghien cuu SGK va HS thao luan cho ket qua: cho bi^t: - The nao la anh kim? Anh kim la anh sang thu dugc kim loai hap thu anh sang trang va phan xa anh sang co buac song dac trung cho timg kim loai Gidi thich: Do cac dam may electron tudo tinh the kim loai hap thu phan xa hau het nhirng tia sang nhin thay dugc, do kim loai co ve sang lap lanh ggi la anh kim - Giai thich HS nhan xet: Tinh chdt vdt li chung ciia GV huang dan HS ket luan vin de: kim logi gdy nen boi su cd mat ciia cdc Nguyen nhan gay tinh chat vat li electron tu cd mat tinh thi kim logi chung ciia kim loai? Tinh chat rieng GV giai thieu: Ngoai cac tinh chat tren HS nghe giang kim loai co mgt so tinh chat vat U khac nhu: Tinh cung, khoi lugng rieng, nhiet nong chay, nhiet soi a) Khdi luang riing GV cho HS nghien cim SGK va yeu HS nghien cuu SGK va nhan xet ciu HS cho biet sir bien doi cac tinh Khoi lugng rieng ciia cac kim loai khac chit: Tinh cimg, kh6i lugng rieng, ro ret nhu: nhiet nong chay, nhiet soi - Ll (D = 0,5 gam/cm ) la kim loat nhe nhat - Os (D = 22,6 gam/cm ) la kim loai nang nhat Hogt dpng cua GV Hogt dpng cda HS b) Nhiet dp ndng chay Nhiet nong chay cua kim loai dao dgng mgt khoang rgng nhu: Kim loai co t°,thip nhit la Hg(-39"C) Kim loai co t°,cao nhit la W(3410°C) c) Tinh cirng Tinh cicng ciia kim loai ciing rat khac nhu: Cr la kim loai cirng nhat, kim loai ki6m thi rat mem co the dung dao de cat Hogt dpng II TINH C H A T H O A H O C CHUNG CUA KIM LOAI GV huong dan HS rut tinh chat hoa HS thao luan nhan xet cho ket qua sau: hgc ca ban ciia kim loai: - Kim loai thuang co it electron (l-3e) - Dac diem cau tao cua nguyen tir kim a lop ngoai ciing loai (so electron hoa tri) - Xu huang cho electron de dat dugc - Du doan xu huang ciia kim loai de cau hinh ben CO dugc cau hinh ben cua hiem - Tinh chat chung cua kim loai la tinh - Suy tinh chat chung cua kim loai khir M ^M""+ne Hogt dpng \ Tac dun vol phi kim GV giai thieu: Kim loai co the tac HS thao luan cho ket qua: dung vai nhieu phi kim a nhiet cao Kim loai tac dung vai phi kim tao Yeu cau HS cho biet san pham, lay vi muoi (trir oxi) du minh hoa F/t/w.-2Fe +3C12 ^—> 2FeCl3 2A1 + 302 -^-^ Fe + S - ^ ^ FeS 2AI2O3 Hogt dpng cda GV Hogt dpng cua HS Hogt dpng Tac dung voi dung dich axit a) Ddi v&i dung djch HCl, H2SO4 hang GV neu vin At Cac dung dich axit HS thao luan de giai quyet van de: HCl, H2SO4 loang co tinh oxi hoa Nhung tai chi tac dung dugc vai cac kim loai dimg truac H day hoat dgng? San pham phan ung thu dugc la gi? GV huang dan HS Giai quyet vin dh, Viet cac phuang trinh hoa hgc minh hoa Cac phan tir axit HCl, H2SO4 loang co tinh oxi hoa ion H phan tir axit the hien nen chi tac dung vai cac kim loai CO tinh khir manh han hidro San pham phan img la muoi va H2 Phuang trinh hoa hgc phan ung: Zn +HC1 -> ZnCb + H t GV bo sung: Cac kim loai da hoa tri thuang bi oxi hoa len so oxi hoa trung binh nhu: Fe, Cr Fe —> Fe Zn + H2S04 ^ ^ ZnS04+ H2T +2 b) Ddi v&i, H2SO4 (dgc,ndng), HNO3 GV dat vin dk: Tai HNO3, H2SO4 dac lai tac diing dugc vai hau het cac kim loai (trir Au, Pt) Trong axit HCl, H2SO4 loang khong co dugc tinh chat nhu vay? GV huang dan HS giai quyet van de HS thao luan de giai quyet vin de duai su huong dan ciia GV: + +6-2 +1 +5 -2 - S6 oxi hoa cua cac nguyen to - So oxi hoa: H2 SO4, H N O3 phan til- axit ITNO3, H2SO4 Hogt dpng cua GV Hogt dpng cua HS Cau Tim cdng thiic hoa bgc dang phan tii va dang hgp chit kep cua nhirng chit ed phan nhu sau: a) Hgp chit A: 32% Na, 12,9%Al, 52,9%F Cau a) Thanh phan khdi lugng hgp chat A: 32,9% Na; 12,9%) Al; 54,2% F _ 32,9 12,9 54,2 riNa- OAI: np • • 23 27 19 Cdng thiic chung ciia criolit la: Na3AlF6 hay 3NaF.AlF3 b) Thanh phan khoi luong hgp chit B: 14%) K; b) Hgp chit B: 14%K; 9,7%Al; 9,7% Al; 30,5% Si; 45,8% O 30,5%Si; 45,8%0 Tinh tuong tu nhu tren ta dugc cdng thirc chung la KAlSi308 hay KAl02.3Si02 Cau Cd Ig dung rieng biet Cau Cd Ig dung rieng biet eac dung dich: cac dung dich: NaCl, CUSO4, NaCl, CUSO4, HCl, NaOH HCl, NaOH NaCI a) Trinh bay each nhan bilt timg chat dung mdi Ig, vdi dieu kien khdng dung them thudc thir nao khac b) Hay tu chgn mdt thudc thir de sir nhan biet cac chat tren trd nen don gian ban Trinh bay each nhan biet va viet phuang trinh hoa hoe CUSO4 HCl NaOH NaCI CUSO4 i xanh HCl Ong nghiem ndng NaOH ixanh Ong nghiem dng Tien hanh thi nghiem nhu bang tren ta se suy dugc: - Neu ca dng nghiem deu khdng cd hien tugng gi, dd la dung dich NaCl hoac HCl - Neu ca dng nghiem khdng ed hien tugng, dng nghiem ed ket tiia xanh, dd la CUSO4 hoac NaOH 175 Hogt dpng cua GV Hogt dpng cua HS - Cho ket tua mau xanh vao dng nghiem cdn lai Nlu kit tua tan dd la dung djch HCl Nlu kit tiia khdng tan, dd la NaCI - Dun ndng dung dich CUSO4 va NaOH Nlu mau xanh cua dung dich dam din thi la dung dich CUSO4, neu mau khdng ddi thi dd la dung dich NaOH HS viet cae phuang trinh hoa hgc b) De su nhan bilt eac chit tren trd nen don gian ban ta dimg mdt thudc thu la nhdm Yeu cau HS neu each tien hanh nhan bilt va vilt eac phuang trinh hoa hgc GV eho HS lam them cac bai tap sau: Cau Trong qua trinh san xuit nhdm cdng nghiep khoang chat criolit (Na3AlF6) dugc sii dung vdi muc dich chinh la Cau Chgn dap an C A tao hdn hgp cd kha nang dan dien tdt hon so vdi ban dau B tao ldp bao ve nhdm ndng chay khdi su oxi hoa cua oxi khdng C tao hdn hgp ed nhiet ndng chay thap ban so vdi ban dau D tao ldp bao ve dien cue khdi bi an mdn Cau Khi dl khdng nhdm khd bi an mdn hon sit la 176 Cau Chgn dap an B Hogt dpng cda GV Hogt dpng cua HS A nhdm cd tinh khir manh ban sit B tren be mat nhdm cd ldp AI2O3 ben vimg bao ve C nhdm cd tinh khir yeu hon sat D tren be mat nhdm cd Igp A1(0H)3 bao ve Cau Hoa tan 21,6 gam Al Cau Chgn dap an D mdt dung dich NaN03 va NaOH du Tinh thi tich NH3 d dieu kien tieu chuan thoat neu hieu suat phan img la 75%) A 2,24 lit B 4,48 lit C 6,72 lit D 5,04 lit Cau De tinh che quang boxit Cau Chgn dap an A (AI2O3 ed lan Si02 va Fe203) ngudi ta cho quang (dang bdt) lan lugt tac dung vdi cae chat: A NaOH, CO2 B HCl, CO2 C NaOH, CuCb D HClvaNH3 Cau Cho 16,2 gam kim loai M Cau Chgn dap an B tac dung hoan toan vdi 0,15 mol oxi, chat ran thu dugc tac dung het vdi dung dich HCl tao 0,6 mol H2 Kim loai M la A Fe B Al C Ca D Mg 12- TKBG HOA HQC 12 NC-T2 177 Hogt dpng cua GV Hogt dpng cua HS Hogt dpng BAI TAP VE NHA GV yeu cau HS ve nha lam them cac bai tap sau Cau 1: Mdt hon hgp X gdm K va Al cd khdi lugng la 10,5 gam Hoa tan X nude thi hdn hgp X tan het eho dung dich A a) Them tir tir mdt dung dich HCl IM vao dung djch A Khi diu khdng cd kit tiia Ke tir the tich dung dich HCl 1M them vao la 100 ml thi dung dich A bit diu co ket tua Tinh % mdi kim loai hon hgp X b) Mdt hon hgp Y ciing gdm K va Al Trdn 10,5 gam hon hgp X tren vdi 9,3 gam hdn hgp Y dugc hdn hgp Z Hon hgp Z tan het nude cho dung dich B Them HCl vao dung dich B thi gigt dau tien dung dich HCl them vao da co ket tua Tinh khdi lugng K va Al hdn hgp Y Bai Hoa tan 2,16 gam hdn hgp kim loai Na, Al va Fe vao nude du, Thu dugc 0,448 lit (dktc) va cdn lai mdt lugng chat rin Cho lugng chat rin tac dung het vdi 60 ml dung dich CUSO4 IM thu dugc 3,2 gam Cu kim loai va dung dich A Cho dung dich A tac dung vdi mdt lugng vira du NH4OH thu dugc kit tua Nung ket tiia thu dugc khdng din khdi lugng khdng ddi dugc chit rin B a) Xac dinh khdi lugng timg kim loai hon hgp diu b) Tinh khdi lugng chat rin B Bai Cho hdn hgp bdt Al va Fe203 Thuc hien phan img nhiet nhdm hon hgp dieu kien khdng cd khdng Chia hdn hgp thu dugc sau phan ung(da trdn deu) hai phin Phin tac dung vira dii vdi 100ml dung dich NaOH 2M, thu dugc dung dich A va can rin D.Phin tac dung vira dii vdi l,12lit dung dich HCl IM thu dugc dung dich B va ddng thdi thu dugc 2,4 lit H2 (do d 19,5'^C va atm).Biet rang hieu suit eac phan img diu la 100%o a Tinh khdi lugng sat tao phan iing nhiet nhdm b Xac dinh khdi lugng can ran D c Xac dinh khdi lugng va phin %) theo khdi lugng cua hon hgp diu 178 Bai 36 BAI THU'C HANH TfNH C H A T C U A K I M LOAI KIEM, KIM LOAI KIEM T H VA HOP CHAT CUA CHUNG A MUC TIEU BAI HOC LKilnthCpc • Ciing CO he thdng tinh chat hoa bgc cua mdt sd kim loai kilm, kim loai kilm thd va hgp chat eiia chung • Giiip HS biet each tien hanh mdt sd thi nghiem: - So sanh phan ung eiia Na, Mg, Al vdi nude - Phan img cua MgO vdi nude - So sanh tinh tan ciia muoi CaS04 va BaS04 KT nang • Ren luyen tinh than trgng chinh xac tiln hanh thi nghiem • Sir dung dung eu boa chat de tien hanh dugc cdng cac thi nghiem • Ren luyen kT nang quan sat, neu va giai thich hien tugng • Viet tudng trinh thi nghiem Tinh cam, thai Thdng qua boat ddng thi nghiem tao nen thii hgc bd mdn boa hgc B C H U A N Bj CUA GV VA HS • GV: - May tinh, may chieu, cae phieu hgc tap - Hoa chat: +Kim loai: Na, Mg, Al + Dung dich: CaCb, BaCb, BaS04 + Giay phenolphtalein - Dung eu: + Ong nghiem, den cdn + Cdc thuy tinh + Bd gia thi nghiem • HS: - Xem trudc bai thuc hanh 179 C TI^N TRiNH DAY - HOC Hogt dpng cua GV Hogt dpng cda HS Hogt dpng DAN DO TRLfdC BUOI THU'C H A N H GV neu eac ndi dung chinh cua budi HS nghe GV trinh bay va thao luan thue hanh theo nhdm thuc hanh - GV yeu cau HS trinh bay cae y kien lien quan den budi thuc hanh - Luu y HS dimg boa chat vira dii va sir dung can than eac dung eu thi nghiem - Chia ldp bgc eac nhdm thuc hanh mdi nhdm gdm 4-5 HS I NOI DUNG THI NGHIEM VA CACH TIEN HANH Hogt dpng Thi nghiem SO S A N H K H A N A N G P H A N CUA Na, Mg, Al vOl NLfCJC LTNG GV eho HS nghien ciiu SGK va eho HS nghien eiiu SGK va len bang tien HS len ban thi nghiem tien hanh ba thi hanh thi nghiem: HS 1: Rdt nude vao dng nghiem thii nghiem SGK nhat khoang 3/4 dng, them mdt it phenolphtalein rdi bd vao dd mdt mau Na bang hat gao HS 2: Rdt nude vao dng nghiem thii khoang 5ml, them mdt it phenol phtalein rdi bd vao mdt mau Mg Sau dd dun ndng dng nghiem HS 3: Rdt nude vao dng nghiem thii ba khoang 5ml, them mdt it phenolphtalein rdi bd vao dd mdt mau Al Sau dd dun ndng dng nghiem 180 Hogt dpng cda GV Hogt dpng cda HS HS quan sat cho nhan xet Ong nghiem thir nhat: Thay mau Na phan ling manh vdi nude cd thoat manh va dung dich chuyen sang mau hdng GV hudng dan HS quan sat va so sanh Gidi thich: Kim loai Na phan iing manh hien tugng d dng nghiem, giai thich vdi nude tao H2 va dung dich baza va viet phuang trinh boa bgc xay lam phenolphtalein boa hdng GV hudng dan HS giai thich thi Phucmg trinh hod hoc nghiem 2Na + H2O -> 2NaOH + H2T dng nghiem thir hai: Thay mau Mg phan img cham vdi nude cd bgt li ti thoat Khi dun ndng thi phan img xay manh hon va dung dich chuyen sang mau hdng 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 dng nghiem thii ba: Thay mau Al hau nhu khdng ed hien tugng Gidi ihich: Kim loai Al phan iing nude tao ldp oxit ben ngan cho phan ung xay ke ca dun ndng Phuang trinh hod hoc: 2A1 + 6H2O 2A1(0H)3 > 2Al(OH)3 + 3H2 -> AI2O3 + 3H2O 181 Hogt dpng ciia GV Hogt dpng cda HS GV bd sung: Neu pha bd ldp oxit dd (hoac tao hon hong Al-Hg), thi nhdm se tac dung vdi nude d nhiet thudng Hogt dpng Thi nghiem P H A N LTNG CUA MgO vOl NLTOC GV lam thi nghiem: HS quan sat va nhan xet: Hiin tugng: Ban dau dung dich lam - Nhd tiep vao dng nghiem 10 gigt giay tam phenol phtalein ed mau hdng nhat Khi dun ndng cho mau giay tam nude, lac nhe phenol phtalein khdng ddi mau - Lay mdt gigt chat long tir san pham Gidi thich: phan img tren nhd vao manh giay tam - MgO tac dung vdi nude tao dung dich phenolphtalein - Cho vao dng nghiem mgt it bdt MgO - Dun sdi chat long, de ngudi va thir bang Mg(0H)2, (dung dich baza) lam hdng phenolphtalein giay tam dung dich phenolphtalein MgO + H2O -> Mg(0H)2 Yeu eau HS quan sat, neu hien tugng giai thich va viet phuang trinh boa bgc - Dun sdi dung dich thi Mg(0H)2 bi GV hudng dan HS giai thich thuy phan MgO va nude nen khdng lam ddi mau giay tam dung dich phenolphtalein Mg(0H)2 ^ ^ MgO + H2O Hogt dpng Thi ngli'iem SO S A N H TINH TAN CUA MUOI CaS04 v A BaS04 GV eho HS nghien cim SGK yeu cau HS nghien ciiu SGK va cho kit qua: chuan bi hoa chat va tien hanh thi - Hoa chat: Dung dich BaCb, CaC^ ciing nghiem ndng do, dung dich CUSO4 GV hudng dan HS giai thich va kit luan 182 - Dung cu: Ong nghiem, dng hut nhd gigt Hogt dpng cua GV Hogt dpng cda HS Tiin hdnh thi nghiem: Cho ml dung dich CUSO4 vao dng nghiem mdi dng chira 1ml dung dich BaC^, 1ml dung dich CaC^ - Hien tugng thay dng nghiem chira BaC^ xuat hien nhieu ket tua han dng nghiem chira CaC^ - Gidi thich: •* Ong nghiem BaC^ BaCl2 + CuS04 ^ BaS04i+CuCl2 Ong nghiem CaC^ CaCl2 + CuS04 -^ CaS04i+CuCl2 Do dung dich BaC^, CaC^ ed cimg ndrig va the tich nen sd mol BaS04, CaS04 tao la nhu ma dng nghiem chiia BaS04 nhieu ket tiia ban chiing td BaS04 it tan ban so vdi CaS04 - Kit ludn: Mudi BaS04 it tan hon so vdi • mudi CaS04 Hogt dpng II CONG VIEC SAU BUOI THlTC HANH GV nhan xet vl budi thuc hanh va HS thu dgn, ve sinh phdng thi nghiem hudng dan HS thu dgn boa chat, riia can than, an toan dng nghiem va dung eu thi nghiem, ve sinh phdng thi nghiem GV yeu ciu HS lam tudng trinh theo HS lam tudng trinh theo miu sau day: mau: 183 Ngdy thdng ndm Ho va ten: Lo-p: T6 thi nghiem: Tu'O'ng trinh hoa hoc bai s6: Ten bai: Ten thi nghiem Phwong phdp tiin hanh Hien twgng quan sdt GISI thich - viit phwong trinh phdn d'ng Bai 37 BAI THU'C HANH TiNH CHAT CUA NHOM VA HOP CHAT CLIA NHOM A MUC TIEU B A I HOC Kidn thiHC • Cimg cd he thdng tinh chat boa hgc dac trung nhdm va hgp chat quan ciia chiing • Giiip HS biet each tien banh mdt sd thi nghiem: - Phan img eiia Al vdi dung dich CUSO4 - Al tac dung vdi dung dich NaOH - Dilu ehi Al(0H)3 - Tinh chat ludng tinh cua Al(0H)3 KT nang • Ren luyen tinh than trgng chinh xac tien hanh thi nghiem • Sir dung dung eu hoa chit de tiln hanh dugc an toan, cdng eac thi nghiem 184 • Ren luyen kT nang quan sat, neu va giai thich hien tugng • Viet tudng trinh thi nghiem Tinh cam, thai Thdng qua boat ddng thi nghiem tao nen hiing thii hgc bd mdn hoa hgc B C H U A N B! CUA GV vA HS • GV: - May tinh, may chieu, cae philu bgc tap - Hoa chat: +Kim loai: Al + Dung dich: NaOH, AICI3, CUSO4 dac, HCl loang - Dung cu: + Ong nghiem, den cdn + Cdc thuy tinh + Bd gia thi nghiem • HS: Xem trudc bai thuc hanh C TI^N TRiNH DAY - HOC Hogt dpng cua GV Hogt dpng cua HS Hogt dpng DAN DO TRLTOC BUOI THI/C H A N H GV neu eac ndi dung chinh ciia budi HS nghe GV trinh bay va thao luan theo thirc hanh nhdm thue hanh - GV yeu eau HS trinh bay cac y kien lien quan den budi thuc hanh - Luu y HS dimg boa chat vira dii va sir dung can than cae dung eu thi nghiem - Chia ldp hgc cac nhdm thuc hanh moi nhdm gdm 4-5 HS 185 Hogt dpng cua GV Hogt dpng cua HS I NOI DUNG THi NGHIEM VA CACH TIEN HANH Hogt dpng Thi nghiem P H A N LTNG CUA Al VOl CUSO4 GV cho HS nghien cim SGK yeu ciu HS nghien cim SGK va nhan xet - Chuan bi cac boa chat - Hoa chat: La nhdm sach, dung dich - Neu phuang phap va tiln hanh thi CUSO4 nghiem - Dung cu: Ong nghiem, cap dng - Neu hien tugng, giai thich vilt phuang nghiem, kep thi nghiem trinh hoa hgc Tien hanh thi nghiem: - Neu ket luan Nhiing la Al da dugc danh sach ldp AI2O3 phii ben ngoai vao dung dich CUSO4 cdc thuy tinh Quan sat hien tugng va giai thich: Cd ldp vay Cu mau dd bam tren mat la Al Ddng thdi dung dich bi nhat mau Do ed phan iing khir Cu 2+ Cu Phuong trinh boa hgc: 2Al + 3Cu^ -^ C u l + 2Al 3+ Hogt dpng Thi nghiem P H A N LTNG CUA NHOM v O l DUNG DICH NaOH GV lam thi nghiem: Rdt 2-3 ml NaOH vao dng nghiem va bd vao mdt mau nhdm Sau dd dun ndng (de phan iing xay nhanh hon) Yeu ciu HS quan sat, neu hien tugng giai thich va vilt phuong trinh hoa hgc HS quan sat va nhan xet: Hiin tugng: Thay mau nhdm tan dan ddng thdi cd thoat Gidi thich: Trong khdng nhdm bi oxi hoa tao mdt ldp oxit mdng ben ngoai bao ve nhdm GV hudng dan HS giai thich (tranh - AI2O3 la oxit ludng tinh nen tac dung trudng hgp HS hieu nham nhdm la kim vdi dung dich kiem tao mudi tan loai ludng tinh) 186 Hogt dpng cua GV Hogt dpng cda HS Al203+2Na0H + H2O -> Na[Al(0H)4] natri aluminat (tan) - Khi khdng cdn mang oxit bao ve, nhdm se tac dung vdi nude tao A1(0H)3 va giai phdng H2 2A1 + 6H2O - > 2Al(OH)3 + 3H9 (1) A1(0H)3 la hidroxit ludng tinh nen tac dung tiep vdi dung dich kiem Al(OH)3 + NaOH^Na[Al(OH)4] (2) Cdng (1) va (2) ta cd phuang trinh hoa hgc sau: 2A1 +2NaOH +6H2O -^2Na[Al(OH)4] + 3H2 Ket ludn: Nhdm cd the tan dung dich kiem va giai phdng hidro Hogt dpng Thi nghiem DIEU CHE Al(0H)3 GV yeu cau HS neu phuong phap dieu HS thao luan eho ket qua che A1(0H)3, tir dd chuan bi cae hoa - Dilu che Al(0H)3 bang each: Cho chat va tien hanh thi nghiem, viet dung dich NaOH hoac dung dich NH3 phuong trinh hoa hgc tac dung vdi mudi Al - Hoa chat: Dung dich AICI3, dung dich NaOH loang - Tien hanh thi nghiem: Cho tir tir timg gigt NaOH loang vao dng nghiem chira - ml dung dich AICI3, lac nhe - Hien tugng: Cd ket tiia keo xuat hien 187 Hogt dpng cua GV Hogt dgng cua HS - Phuang trinh hoa hgc: GV luu V HS: Cho NaOH tir tir khdng AICI3 + NaOH ^ Al(0H)3 i + NaCl dugc du vi A1(0H)3+ NaOH -^ Na[Al(0H)4] tan Hogt dpng Thi nghiem TINH C H A T L U O N G TINH CUA A1(0H)3 GV eho HS nghien eiiu SGK yeu eau HS nghien eiiu SGK va cho ket qua: - HS 1: chuan bi cac boa chat - HSl: Hod chdt: Al(0H)3 d thi nghiem - HS 2: Neu phuang phap va tien hanh tren, dung dich NH3,dung dich H2SO4 thi nghiem loang, dung dich NaOH - HS Neu hien tugng, giai thich viet Dung cu: dng nghiem, dng hiit cap dng nghiem phuang trinh hoa hgc - Neu ket luan - HS 2: Tien hanh thi nghiem Thir tinh chit ciia Al(0H)3 - Lay dng hiit nhd gigt hiit dung djch NH3 cho vao dng nghiem thii nhat chiia Al(0H)3 ddng thdi lac nhe - Lay dng hiit nhd gigt hiit dung dich NaOH eho vao dng nghiem thii hai chiia Al(0H)3 ddng thdi lac nhe - Lay dng hiit nhd gigt hiit dung djch H2SO4 loang vao dng nghiem thir ba chiia Al(0H)3 ddng thdi lac nhe HS 3: Hien tugng va phuang trinh boa hgc Ong nghiem 1: Khdng cd hien tugng Ong nghiem 2: Thay ket tiia keo tan dan cd phan img hoa bgc sau 188 Hogt dpng cua GV Hogt dpng cua HS A1(0H)3 + H "^[A1(0H)4] Ong nghiem 3: Thay kit tua keo tan din cd phan ung hoa hgc sau A1(0H)3 + H " -^ Al^" + 3H2O - Ket luan: Al(0H)3 la hidroxit ludng tinh Hogt dpng II CONG VIEC SAU BUOI THU'C HANH GV nhan xet ve buoi thuc hanh va HS thu dgn, ve sinh phdng thi nghiem hudng din HS thu dgn boa chit, rira can than, an toan dng nghiem va dung cu thi nghiem, ve sinh phdng thi nghiem GV yeu eau HS lam tudng trinh theo HS lam tudng trinh theo mau sau day: mau: Ngay thdng ndm Ho va ten: Lo-p: T6 thi nghiem: Tirvng trinh hoa hoc bai sd: Ten bai: Ten thi nghi$m Phwong phdp tiin hdnh Hien twgng quan sdt Giai thich - viit phwong trinh phan u-ng 189 ... phuong trinh dai so: nx-64 - .10 0% = 9,6% a Rutra: a=^ ^ ^ 0 9,6 (4) Tir (3) va (4), ta co: il(207 ^10 0=i^^^^^.l00 19 9,6 Kim loai M co khdi lugng mol 11 2 la cadimi (Cd) 12 Giai tuong tu bai tap Kim... +0,06 S/H2S +0 ,14 Sn""/ Sn''" +0 ,15 Cu''"/ Cu" +0 ,15 Cu''" + 2e -^ Cu SO4''-/ H2SO3 Cu''"/ Cu +0,34 Fe(CN)=-+1e-> Fe(CN)^- Fe(CN)^-/ Fe(CN)g^- +0,36 Cu"+1e->Cu Cu"/Cu +0,52 I2 + 2e ^ 12 / 21- +0,54 MnO,... 1e -» Na Na"/Na -2, 71 Mg^" + 2e ^ Mg Mg''"/Mg -2,37 H2 + 2e ^> 2H- H2/2H- -2,25 Be^" + 2e -> Be Be''"/Be -1, 85 Al^* + 3e ^ Al AI^"/AI -1, 66 Ti''" + 2e ^ Ti Ti''"/Ti -1, 63 Mn''"+2e^.Mn Mn''"/Mn -1, 18