Tqp chi khoa hoc TrUbng Dqi hgc Quy Nhcfn - Sd'3, Tqp Vll ndm 2013
Sif DUNG THI NGHIEM THl^C HANH NHAM NANG CAO m%\] QUA DAY HOC H 6 A HOC d TRl/OtNG TRUNG HQC P H 6 T H 6 N G
NGO THI NGOC MAP, NGUYEN THI KIM A N H ^
1. M 6 DAU
Vdi dac thii 1^ mon khoa hoc u'ng dung, vi§c day v& hoc Hda hgc khong the thig'u SLf lien he giii'a \^ thuyet va thUc hanh. SiJ dung thi nghiem hda hoc se giup hpc sinh nam vu'ng cac khai niem, dinh luat,... \k rdn luyen cdc ky nang thifc nghiem. Qua do, bo sung kien thu'c mdi, lam sang td nhiJng van de du'dc hoc tren ldp va trong sach vd, tu" do hinh Ihanh phiTOng phdp hoc tap va nghien cu'u khoa hpc, nang cao niem tin vao khoa hpc.
NhiJug nam hpc qua, tuyen sinh Dai hpc nifdc ta thifc hien theo tieu chi 3 chung.
Mon Hda hpc difOc danh gia theo phifpng phap trac nghiem. Vdi quan diem '"hoc gl thi nay" da lam cho viec suf dung thi nghiem trong cac gid len ldp cua giao vien pho thong rat han ch§', hpc sinh thi khong quen hpc theo kieu tif luan, tif minh giai quye^t cac tinh hudng cd van de. Cac tie^t hpc thifc hanh tai phong ihi nghiem k e m hieu qua VI hpc sinh tiS'n h^nh thi nghiem rap khuon va thieu sif sang tao cung nhif due ket kinh nghi6m v^ ky nang thifc hanh. Vdi mong muo'n nang cao hieu qua day va hpc Hda hpc chiing toi da tien hanh nghien cu'u phifPng phap suf dung thi nghiem trong cac gid day ly thuyet va thifc hanh tai tru'dng trung hpc pho thong.
2. NOI DUNG 2.1. Vai tro cua thi nghidm trong day hpc hoa hpc
Thi nghiem cd vai tro rCt quan trong trong nghien cii'u khoa hpc, dac biet trong day hpc Hda hpc.
'... khdng thi hinh dung duac viic gidng dgy hoa hoc trong nha trudng ma lai khong CO quan sdt, khong co thi nghiim hgc tdp" B.P. Exipop [4].
- Thi nghi6m cd vai tro het siJc quan irpng trong qua trinh phat trien nhan thiJc cua con ngifdi ve the gidi. Thi nghi6m gitip con ngu'di tim ra cai ban chat cua sif vat, hi8n ttfdng, phat hien ra quy luat con an nau trong tif nhien. Mat khac, thi nghiem cdn gdp phan kiem chu'ng v^ lam sang td cac gia thuyS't khoa hpc.
- Thi nghiem la nen tdng cua viec day va hpc Hda hpc. Thi nghiem giup hpc sinh hi^u difdc ban chS't cac qua trinh hoa hpc, nam vii'ng cac khai niem, dinh luat, hpc thuyel, tiif do giiip hpc sinh hinh thanh kha nang chuyen ddi tiJf tif duy cu the sang lif duy trifu tifdng va ngu"dc lai.
NG6 THI NGOC MAI', NGUY6N THI KIM ANH' - Thi nghidm 14 cau noi giCfa I;? thuyet vi thiTc te. ThI nghi?m giup hpc sinh rin luyen Ihao tdc thi nghidm, ky n3ng quan sdt hi?n tiTdng, phdn tich, gidi thich, chd'ng minh, thu thap va xU li s^ li$u thiTc nghi?m. Qua id, hlnh thdnh dao diJc vd tdc phong ldm viec ca'n than, l(ien trt, chdm chi, l<hoa hoc, l(y luat.
- Thi nghi$m giilp hgc sinh phdt trien Ichd ndng tl/ duy, sdng tao, hinh thdnh th^
gidi quan duy vat bi^n chdng, lit dd nang cao niem tin vao khoa hpc.
- Cuoi cdng, thi nghidm gidp cho mon hpc khoa hpc khong hi kho khan, hpc sinh de dang tao dddc hdng thu U-ong hpc tap, td dd nang cao sti say mS nghien cdu khoa hpc.
2.2. Nguyen tdc \&y ddng h$ thd'ng thi nghidm thi/c hanh trong d^y hpc hoa hpc Muon thi nghidm di vdo cdc bdi gidng hda hpc d im'dng phd thong mpt each cd hieu qua thi phai xay ddng h$ thdng thi nghiem thdc hdnh tuan thu 8 nguyen tdc sau:
- Thi nghiem phai gdn lien vdi chddng tnnh hda hpc d trddng trung hpc phd thong.
- Thi nghidm phai gdn vdi npi dung bai giang, lam ndi bat kie'n thdc dpng tdm.
- Thi nghiem phai trdc quan, hien tddng ro rdng, co tinh thuyet phue.
- Thi nghiem phai ha'p ddn, kich thich sd hdng thu cua ca gido vien vd hpc sinh.
- Thi nghiem cd hda cha't dl dm, gid thanh tha'p, ddn gian, dd thdc hien.
- Thi nghiem khong dddc mat qua nhieu thdi gian, lam anh hddng de'n tien tnnh bai giang vd thdi Iddng tie't hpc.
- Thi nghidm phai bao dam an todn cho ca gido vien va hpc sinh, han chd' sd dung cdc chat dpc hai.
- Sd Iddng thi nghiem dong mpt tid't day (1^ thuyd't hay thiTc hdnh) phai hdp li, khong nen tid'n hanh qud nhieu thi nghidm anh hddng tdi thdi Idpng giang day.
2.3. Phdn lo^l thf nghidm
2.3.1. Thi nghi$m do, thi nghifm mo phdng - Thi nghidm dddc mo td bang sd dd tinh.
- Thi nghiem dddc xay ddng bang phan mem mo phong.
- Thi nghiem dddc ghi hinh Iai va sd dung de trinh chie'u trong cdc tid't day.
2.3.2. Thi nghifm thtlc hanh
- Thi nghipm bieu dien cua gido vidn: la thi nghiem do gido vien tii tay bieu dien trddc hpc sinh.
- Thi nghiem cua hpc sinh: la thi nghiem do hpc sinh td lam.
- Thi nghidm ngoai khoa: la cac thi nghiSm vui n-ong cdc budi ngoai khda hay thi nghiem thdc hdnh d nhd ciia hpc sinh.
sif DUNG THf NGHIEM T H U C H A N H N H A M NANG CAO HIEU QUA DAY HOC H 6 A HOC 47 Trong cac hlnh thu'c trSn, thi nghiem bieu diSn cua giao vien la quan trpng nhat.
* Uu di^m cua thi nghidm bi^u diln cua giao vien la:
+ Giao vi6n tien h^nh thi nghiem vdi thao tac thi nghiem chuan mi/c se co tac dung hinh thanh cac ky nang thi nghiem dau lien cho hpc sinh mpt c^ch chuan xac.
+ Tiet kiem hda chat, tie't kiem thdi gian.
+ Cd the ihifc hien du'pc mol so thi nghi$m phiJc tap, khd thtfc hien.
* Bi thi nghidm cd ti I^ thanh cfing cao c^n dap ii'ng cac yeu c^u siTpham ve ]a thuSt bi^u dien thi nghidm sau:
+ Phai dam bao an loan: khong diJng lu'png ldn cac chat cd tinh dpc hoac de chay nS, tien hanh thi nghiem than trpng theo diing cac quy dinh ve bao hiem.
+ Phai dam bao ihEinb cong: nam vii'ng cdc ki thuat thi nghiem, thao lac kheo leo.
+ Thi nghiem phai rd rang, dam bao hpc sinh quan sat day du hien tifpng.
+ Thi nghiem phai dPn gian, dung cu iSp dat gpn gang, cd tinh khoa hpc.
+ Tiet kiem thdi gian.
+ So lifdng thi nghiem vfifa phai.
+ Ket hpp chat che vdi npi dung bai giang, dac biet la ki6'n thii'c trpng tam.
2.4. Cac b}i6c ti^'n hanh mpt gioT day ly thuyet co su* diing thi nghidm Birdc 1 Chuan bi
- Ke hoach bai day hoc du'di dang word: xac dinh muc lieu bai day, len kd' hoach ket hPp chpn lpc va phifdng phap suf dung thi nghiem, phan bo' ihdi lifdng hPp li vao bai giang.
- Dung cu, hda chat thi nghiem va tien hanh Iam thuf thi nghiem thanh cdng trifdc khi len ldp. Mo hinh, sd do, mo phong quy trinh san xua't hoac cac thi nghiem dpc hai.
Bifdc 2 Van dung Ihi nghiem vao bai day hpc hda hpc
K6't hdp hiiu dien thi nghiem vao bai giang ly thuyet nhanh, chinh xac, ro rang va dam bao thanh cong.
Btfdc 3 Nhan xet, danh gia
L3,'y '^ kie'n ddng gdp cfia dong nghiep, kiim tra kha nang linh hpi kien IhiJc cung nhif md'c dp hu'ng thii do'i vdi mon hpc cua hpc sinh.
2.5. M$t sd' phtidng phap cd ban sd" dung thi nghidm trong day hpc Hoa hpc Day hpc Hda hpc co the su" dung thi nghidm theo mot trong cac phifdng phap sau:
NGO THI NGOC MAP. NGUYEN THI KIM ANW 2.5.1. Sidling thi nghifm theo phiMng phdp nghien ctiu
Tid'n hdnh thi nghidm dd' nghien cdu kie'n thdc mdi.
Vidu: GV hddng dan HS nghien cdu tinh cha't vat IS cua NHj ldp 11.
GV cho HS quan sdt Ip ddng mau NHj, yeu cau HS nhan xet ve trang thai, mdu sdc, mOi vi. Sau dd GV hddng dan HS ldm TN thd tinh tan cua NH, trong nddc, HS td rut ra nhan xet ve tinh tan cua NH .
- Tan nhieu trong nddc
- Dung dich phenolphtalein chuyen sang hdng.
'•V
2.5.2. Su: d^ng thi nghifm ddi chiing
Dda tren cd sd kie'n thdc da bie't, sd dung thi nghiem de so sdnh, kiem nghiem, td dd khac sau va tich luy kie'n thdc.
Vidu: Bdi "Ddng vd mpt sdhdp cha't cua ddng", net 65, Hda I2-nang cao.
Giao vidn de'n hanh hai thi nghiem:
(1) Cho Id ddng vao dng nghidm diTng dung dich HCI.
(2) Cho Id ddng vao dng nghiem ddng dung dich HNO, lodng.
Hien tddng va kd't luan:
(1) Khong cd hidn tddng gi xay ra. Vay Cu khong tac dung vdi dung dich HCI.
(2) Dung dich HNO, td khong mau chuyd'n sang mau xanh cua mudi Cu-*, ddng thdi thodt khi khong mdu sau dd hda nau hrong khong khi. Vay Cu tdc dung vdi dung dich HNO, loang tao thdnh Cu-* va giai phdng khi NO.
2.5.3. Sit dung TNHH td chdc hoi/t d$ng kiem nghifm gid thuyet, dU dodn gid thuygt Dda trdn cd sd kid'n thdc da cd, phan tich vd neu cdc gia thuyd't, diT doan khoa hpc, sau dd de'n hanh thi nghiem de xdc nhan gia thuyd't, giai thich hien tddng.
Vidu: Bdi 61, ud't 82 chddng trinh Hda 11-nang cao, phan tinh cha't hda hpc cua axit cacboxylic.
Nhdm cacboxyl-COOH dddc ca'u tao td hai nhdm cacbonyl va hidroxyl, nhdm cacbonyl hut electron manh lam cho lidn ke't -O-H trong nhdm hidroxyl phan cdc manh (manh^hdn lien ke't -O-H trong ancol). DiJ dodn axit cacboxyUc cd kha ndng cho proton H* the hidn day du tinh cha't cua mpt axit thong thddng.
Thdc hidn thi nghidm de xac nhan gia thuyd't.
SLf DIJNG THi NGHIEM T H U C HANH NHAM NANG CAO HIEU QUA DAY HOC HOA HOC 4 9
Thi nghiem 1: Cho qu^' tim vao dung dich CH3COOH.
- Hien tu'dng: Quy tim chuyen sang mau hong.
Thi nghiem 2: Cho Zn tac dung vdi CH,COOH.
- Hien tu'dng: Xuat hien bpt khi khong mau vay xung quanh vien kem roi thoat ra ngoai dung dich.
Thi nghiem 3: Cho CH.COOH tdc dung vdi Cu{OH)j.
- Hien tu'dng: Ke't tija xanh bi hoa tan tao dung dich dong nha't mau xanh dac tnftig cua muoi Cu-*.
Thi nghiem 4: Cho CaCO^ tac dung vdi CH,COOH. Khi thoat ra du'dc dSn vao 6'ng nghiem c6 difng dung dich nu'dc voi trong.
- Hien tu'dng: Vien da voi tan dan va xua't hien khi khdng mau thoat ra khoi dung dich. Khi thoat ra lam van due dung dich nifdc voi trong.
2.5.4. Svr dung thi nghifm theo phUofng phdp phdt hien va gidi quyet van de Su* dung thi nghiem de phat hien van de mau thuin vdi kien thu'c da biet va tim hu'dng giai quyet.
Vidu: Bai 6, tiet 11 chu'dng trinh Hda I l-nSng cao, phan sif thuy phan cua muoi.
Thi nghiem: Cho 3 ong nghiem khong mau, khong dan nhan di/ng mpt trong ba dung dich NaOH, NaCI va HCI. Chi dung quy tim de nhan biet ba dung dich tren?
- Quy tim hda xanh la dung dich bazd (NaOH).
- Quy tim hda do la dung dich axit (HCI).
- Quy tim khong doi mau la dung dich muo'i (NaCI).
Giao vien dat van de: Vay cd phai dung dich cua tat ca cac muoi deu cd moi tru'dng trung tinh va khong lam doi man quy lim hay khong?
Thirc hiSn thi nghiem tu'dng tif vdi dung dich muoi Na,C03, CH^COONa, AlCl^
va NH^Cl. Tai sao dung dich muoi Na^CO, v^ CH,COONa lam quy tim chuyen sang mau xanh, dung dich muoi AICI3 vh NH^Cl lam quy lim hda hong?
2.5.5. S& d^ng thi nghidm hoa hQc to chvtc cho HS nghien cvtu tinh chat cdc chat Nghien ciJu tinh chat cua hdp chat mdi difa tren tinh chat cua cac chat da bie't.
Vidu: Bai 5, tie't 7 chifdng trinh Hoa I2-nang cao, phan tinh chat hoa hpc cua Glucozd.
Tir cac diJ kien thifc nghiem, Glucozd cd ca'u tao cua andehit ddn chiJc va ancol 5 chiJc, cd cdng thu'c ca'u lao thu gpn la CHpH-CHOH-CHOH-CHOH-CHOH-CH=0.
Nhifvay Glucozd CO tinh cha'l cua poliancolcd cac nhdm-OH lien ke va tinh chat cua andehit.
50 NGO THI NGOC MAI% NGUYEN THI KIM ANtf Tien hanh thi nghiem:
Cho vao ong nghiem lan lu*dt vai gipt dung dich CuSO^ 0,5%, 1 ml dung dich NaOH 10%. Sau khi phan u'ng xay ra, gan bd phan dung dich dif, giff lai ke't tiia Cu(0H)j.
Cho them vao dd 2 ml dung dich glucozd 1%. L^c nhe ong nghiem.
Hien tu'dng: Ket tua Cu(OH), mau xanh lam tan het tao dung dich dong nhat mau xanh tham do cdc nhom -OH lien ke trong glucozd da tao phii'c vdi ion Cu^*.
Tie'p luc dun ndng dung dich phiJc Iren.
Hien tifdng: Dung dich dan xua't hien ke't lua mau do gach do Cu-* trong phii'c da bi nhdm -CHO khijf xud'ng Cu,0.
Thifc hien phan u'ng trang gifdng cua glucozd, kim loai bac diTdc giSi phong bam vao thanh o'ng nghiem.
2.6. Tid'n trinh mpt buoi day thi/c hanh hda hpc
Theo chiing toi, mgt gid day thifc la mot gid lam viec khoa hpc nghiem tuc. Qua gid hpc thyc hanh hpc sinh khong chi nhan bie't dUdc mpt so dung cu v^ hda chat cd ban mh con hinh thanh ky nang suf dung va tien hanh thi nghiem hieu qua. Qua thUc tiln giang day toi thay phifdng phap day thifc hanh Iruyen thd'ng Ih giao vien cung cap quy trinh thi nghiem va hpc sinh thifc hien may mdc da lam ban che' hieu qua cua viec day hpc va lam giam kha nang tif duy sang tao cung nhif hu'ng thii hpc tap cua hpc smb. Xua't phat tiif tinh than chu dao "lay hpc sinh lam trung tam" va muc tieu lam the nao de khong chi hpc sinh chuyen Hda ma ca cac hpc sinh khong chuyen Hda cung thich hpc Hda va lam thi nghiem Hda hpc, chiing toi da ap dung viec ddi mdi phifdng phap day thifc hanh hda hpc theo phu'dng phap Spickler [1],
Theo Spickler, muo'n phat huy du'dc linh tich ciJc cua viec hpc qua thUc nghidm, can lien hanh ba giai doan:
Giai doan I: Giai doan khao sat tham do
Hpc sinh tif vach ra each lien hanh hoac co the tim kiem thi nghiem va tham khao trong sach giao khoa hoac qua mang internet. Giao vien chi cung cap muc tieu thi nghiem va cd set ly thuyet ma khong cung ca'p each thu'c tiS'n hanh ti mi.
Giai doan 2: Giai doan sang tao
Yeu cau hpc sinh tif thie't ke each thi/c hien, tien hanh, phan tich so lieu va hinh thanh gia thie't.
Giai doan 3: Giai doan kham pha, phat minh va kiem tra gia thie't qua thi nghiem Yen cau cua m^t tiet dgiy thi nghidm thtfc hanh phai d^y du cac phan sau:
* Trirdc budi thi nghiem
sif DUNG THI NGHlfeM THUC HANH NHAM NANG CAO HIEU QUA DAY HOC H 6 A HOC 5 1 - Giao vi6n cung cap thong tin ve:
+ Muc lieu thi nghiem: ten thi nghiem, cdc yeu cau can dat difdc ciia thi nghipm.
+ Cd sd 1^ thuyet: kien thii'c hda hpc chinh xdc de tiS'n hdnh thI nghidm thanh cong.
+ Dung cu, hda chat thi nghiem: dung cu va hda chat can thiel, each sij" dung va mOt sd lifu f ve an todn khi si3f dung thid't hi vd hda chd't.
- Hpc sinh cin tim hieu trifdc cac bifdc lien hdnh thi nghiem va mpt so lull ^ de thi nghiem difdc thdnh cong vd an todn.
* Trong budi thi nghidm
- Hpc sinh tien hdnh thi nghiem va tu" rut ra them mdt sd lull y ve ky nang sijf dung dung cu, hda chat cung nhu" cdch thiJc de lien hdnh thf nghiem thdnh cong.
- Thu thap ket qua thi nghiem.
- Giao vien giam sal va cd su" gidp dd khi can thie't.
* Cudi budi thi nghiem
- Hpc sinh: Phan lich ke't qua thi nghiem va bao cao.
- Giao vien nhan xet kel qua, du'a ra can h6i kiem ira va met rpng.
Vidu: Tiel 68, bai thUc hanh sd 05: Tinh chat cua oxi, lull huynh Thi nghiem 1: Tinh oxi hda cua oxi
* Tnfdc budi thi nghiem - Gido vien cung cap thdng tin ve:
+ Muc dich cua thi nghidm
- Nghien ciJu kha ndng phan i?ng cua O^ vdi Fe.
- Ren luydn ky ndng xoan day Fe, dot day Fe trong binh chu'a O, (du'a day Fe qua mieng Ip thdy tinh, khong cham vao thdnh Ip), quan sdi hien tifdng.
+ Ca sd ly thuyd't
- Fe la kim loai chuyen tie'p, 6 6 26, thupc nhdm VIIIB, chu ki 4 cua bang tuan hodn, cau hinh electron: 1 s^2s^2p^3s^3p*3d*4s^. Fe co tinh khii' d mu'c trung binh, sd oxi hda thu'dng gap trong cac hdp chd'l Id +2 vd +3.
+ Dung cu vd hda chat
- Dung cu: Lp thiiy tinh mieng rpng, den cdn, giay lau.
- Hda chat; Khi Oj, day phanh xe dap (da cuon thanh hinh 16 xo) cd mpt dau g^n vdi mdt thanh gd nhd va dau kia cua 16 xo gan vdi mOt mau que diem, nu'dc hoac cdt.
NGO TBI NGOC MAI', NGUYEN THI KIM ANH*
Hoc sinh: tim hieu trong sdch gido khoa hodc Ira ctfu tdi lieu tham khao vd mang internet ve cdch thtfc tien hdnh thi nghidm.
+ Ciic bifdc lien hanh thi nghipm
- Thu khi oxi vao Ip thuy tinh (do gido vien dieu che' sJn), day lo co mot Idp nifdc mong hodc mpt Idp cat mong.
- Lay sdi day Fe nho, tdt nha't Id day phanh xe dap ddi dp 30 cm cupn thdnh 16 xo. C^m mpt dau cupn day vdo thanh go nho, dau kia cupn ddy kep chdt khoang 1/3 que diem. Dot chdy phan que diem rdi tCf tif difa vao Ip difng oxi.
- Quan sat hien tifdng (anh sang, mdu s^c, dau day Fe, thanh Ip thuy tinh,...).
- Nhan xdt.
* Trong budi thi nghiem
Hpc sinh lie'n hanh thi nghiem, thu thap ke't qua va hinh thdnh ky ndng thi nghiem.
+ Mpt so' lifu y de thi nghiem thifc hien thanh cong.
- Tdt nhat Id nen dung mpt sdi day thep tach ttf day phanh xe dap.
- Trong Ip thuy linh chtfa oxi phai co mpt Idp nifdc mdng hoac ldp cdt mong.
- Phan tfng chay cua Fe xay ra d nhidt dp cao, do dd phai gan mot mau diem d dau 16 xo de cung cap nhidt ban dau cho phan tfng.
- Ne'u day thep gi phai danh sach trtfdc khi do't.
* Cuoi budi thi nghidm
Hpc sinh thu thap kd't qua, phan tich vd bao cdo.
+ Phan lich kd't qua thi nghiem va bao cao - Sat chay trong oxi theo phu'dng trinh hda hpc
3Fe + 2 0 , — ^ F e . O ^
- Phan tfng dot chdy sat trong oxi la phan tfng toa nhiet ldn.
- Que diem chay manh lam cho sdi day thep nong len va chay, nhi?ng tia sang ban tde ra cac hat oxit sat ttf (Fe,0^) mdu nau den bdm d thdnh lp, dau day thep co cue thep hinh cau nho la do ct nhiet dp cao thdp ndng chay vd do stfc cang be mat lam cho no CO dang hinh cau.
Giao vien nhan xet vd dUa ra cau hdi md rpng kie'n thtfc.
+ Cau hoi kiem tra va md rgng
- Vi sao phai xoan sdi day Fe vd dau day Fe phai kep mpt mau diem?
- San pham ciia phan tfng ddt chay Fe trong O^ la gi? Vi sao?
Sl/ DUNG THf NGHIgM THUC HANH NHAM NANG CAO HIEU QUA DAY HOC HOA HOC 5 3 - Trong thi nghidm dot chdy sat trong oxi, ldp nifdc mong hoac ldp cat mong d ddy lp thuy tinh cd tdc dung gi?
- Cd the nhan bie't san pham cua phan tfng dd^t chay sat trong oxi bang each nao?
So sdnh giQa phuang phdp dgy hgc truyen thong va dgy hgc theo phuang phdp Spickler chung toi rdt ra bdng tong ket sou:
T T 1
2
3
Phtffftig p h a p t r u y d n thd'ng Thi nghiem kiem chting, cung cap cho hgc sinh qua tai lieu - Cung c a p ly thuyet thi nghid™
tru'dc khi tid'n hdnh thi nghidm.
- Tid'n hanh thi nghiem chinh xac va ti mi nhif tai lieu htfdng dan.
- M6 ta chi tid't hien tifdng, each tinh loan, phan tich ke't qua thi nghiem va giai thich ke't qua va hien lifdng quan sat difdc.
Muc dich dgt dugc
- Hpc sinh kie'm tra lai hidn ttfdng vd tinh chat hda hpc difdc hpc tai ldp.
Qud trinh hgc lap
Tudn theo ttfng btfdc m o t ciia nhtfng thi nghiem cho sdn.
- Giao vidn giang trifdc khi hoc sinh tid'n hdnh thi nghidm.
Phtftfng p h a p Spickler Thi nghiem da hgc sinh tyC khdo sdt theo hudng ddn
- Cd the' cung c a p ly thuyd't thi nghiem hoac yeu cau hpc sinh tim hid'u theo yeu cau cua giao vidn.
- Hu'dng dan stf dung thie't bi vd dung cu thi nghiem.
- Hpc sinh trinh bay each lien hanh, giao vien kiem Ira lai tinh kha thi cua thi nghidm hoac cho gdi y.
- Khdng cung cap chi tid't ve each lie'n h a n h thi nghiem, each tinh loan, phan tich ke't qua va giai thich ke't qua thi nghiem.
Muc dich dgt dugc
- Hpc sinh tif vach ra cac bifdc tid'n hdnh thi nghidm.
- Hpc sinh tif thu thap so' Hdu.
- Hpc sinh phan thich nhu'ng gi Ihu thap dtfdc vd difa ra ke't luan.
Qud trinh hgc tap
- Qua trinh thtfc hidn tim toi vd khdm phd.
- Giao vien nhan xet vd ddnh gia qua trinh hpc vd ciing co kie'n thtfc.
3. T H U C NGHIEM SU PHAM
Chung toi dd tid'n hanh thtfc nghiem stf.pham trong ndm hpc 2011-2012 tai ldp 11 chuydn Toan (1 IT, 20HS) vd ldp 11 chuyen Ly (UL, 28HS) tnfdng THPT chuyen Ld QuJ' D6n-Binh Dinh, giao vien giang day Ngo Thi Ngpc Mai. Mdi ldp difdc chia
NOP THI NOPCIVIAF. NGUY6N THI KIM ANH' ldm 2 nhdm (TN vd DC) vdi trinh d$ tddng dddng nhau, ndi dung giang day Id cdc bdi mdi thudc cdc chddng: andehit-xeton va axit cacboxylic. Nhdm TN day hpc cd sd dung dli nghiem va nhdm DC day hpc truyin thd'ng khdng sd dung thi nghiem. Ket thuc chddng trinh, chdng toi de'n hanh kiim tra 90 phut (dang trdc nghidm ket hdp tt;
luan, de kid'm tra vd dap an gio'ng nhau, ciing gido vidn cham) tai 2 nhdm (TN vd DC) dca 2 ldp llTvd IlL.
De' ddnh gid hieu qud cua vide sd dung thi nghiem thdc hdnh trong qud trinh day hpc hda hpc d trddng THPT chung toi sd dung cong cu: Bdng kiim quan sdt va bai kiem tra cua hoc sinli [1], [5].
Dda vao cdc bid'u hien cua NLTD chung toi da xay ddng bang kiem quan sdt ddnh gid NLTD cua hpc sinh. Ke't qua cho diem nhd sau:
Bang 1. Tong hap ket qud theo bang kiem quan sdt bieu hien ndng luc tu duy cua HS khi luyen tap
Ldp I I T
I I L
Do'i tddng T N ( I O H S ) DC (10 HS) TN (14 HS) DC (14 HS)
Diem QS trddc TN 55; 56 56; 54 57; 58 57; 57
D i e m QS khi TN 7 I ; 7 3 55; 57 73; 73 58; 59 Bang 2. Tong hgp tham so'ddc trUng iheo quan sdt Tham so' thd'ng ke
Trddc TN
S a u T N
TN DC TN DC
X 56,5 56,0 72,5 57,25
' S F I
0.708
0.935
P 0,620
2,67.10'
+ Ttt gid tri trung binh cho tha'y khi sd diing thi nghiem thdc hdnh trong qua dinh day hpc hoa hpc HS cd diem quan sdt cao hdn nhieu.
+ Xac dmh mdc dp anh hddng: Ttt gid tri r^^ ( >0,7) va p (< 0,05) cho tha'y viec sd dung thi nghidm thdc hdnh trong qua trinh day hpc hoa hpc da cd tac dpng ldn dd'n qua trinh phdt trien NLTD hda hpc cua hpc sinh.
Ke't qua cdc bdi kie'm da sau thdc nghidm nhd sau:
stf DUNG THl NGHIEM THUC HANH NHAM NANG CAO HIEU QUA DAY HOC HOA HOC
Ldp
I I T (20) IIL (28)
Doi tddng TN (10) DC (10) TN (14) DC (14)
Bdng 3. Ket qud ciia bdi kiem tra Dilm X.
0 0 0 0 0
1 0 0 0 0
2 0 0 0 0
3 0 1 0 0
4 0 1 0 I
5 0 1 I 2
6 1 2 2 2
7 3 2 3 5
8 4 2 6 4
9 1 I 1 0
10 1 0 1 0 Bang 4. Bdng phdn hgi ke
Yd'u k e m (0 - 4 diem) TN 3,03%
DC 6,06%
Trung binh (5, 6 diem) TN 15,15%
DC 24,24%
qud hoc tap cda hoc sinh (%}
Khd (7, 8 diem) TN 63,63%
DC 66,67%
Gidi (9, 10 die'm) TN 18,18%
DC 3,03%
Bang 5. Bdng tdng hgp cdc iham so thong ke
Tham s6' thd'ng kd
TN DC
X 7,515 6,788
*hh
0,857
' S B
0,923
P
0,031677
Trdn cd sd ke't qua thtfc nghiem chung loi nhan tha'y:
- Diem trung binh bai kid'm tra cua cac ldp TN luon cao hdn cdc ldp DC Ti Id (%) hoc sinh dat diem ydu kem, trung binh cua cac ldp DC luon cao hdn cac ldp TN, ll Id (%) hpc sinh dat diem kha, gioi d cac ldp TN luon cao hdn cac ldp DC. Dieu nay chtfng to vide stf dung thi nghidm thtfc hdnh trong qua tnnh day hpc hda hpc da c6 tdc dung phdt trien nang Itfc tif duy tot hdn.
- Gia tri r^^ > 0,7: so' lieu cd dp tin cay cao.
- Gia tri p cua phep kiem chtfng t-test doc lap < 0,05: stf khdc bidt ldn gitfa nhdm TN vd DC, khong cd kha nang xay ra ngdu nhidn.
- So sanh ve thai dp hpc tap trong cac gid luyen tap chung loi con nhan tha'y hpc sinh trong cac ldp TN ludn cd thai dp hpc tap tich ctfc hdn.
4. KET LUAN
Qua thtfc td'nghien ctfu vd ap dung giang day, kiem tra, danh gia chiing toi nhan thd'y viec thu'dng xuydn stf dung thi nghidm vdo bai giang ly thuyd't vd day thtfc hanh
NOO THI NGQC MAT. N G U Y 6 N THI KIM ANH"
theo phddng phdp chu dpng, tich cdc trong trddng trung hpc phd thong la het sdc can thie't. Viec lam ndy khong chi gdp phan nang cao hieu qud truyen thii va tiep thu kien thdc khoa hpc md cdn nang cao niem tin, si/ say md, hdng thu hpc tap mon Hda hoc trong trddng trung hpc pho thong. Chung toi hy vpng kd't qua nghidn cdu nay se gdp phan tich cdc trong vide nang cao hidu qud gido due.
TAI LIEU THAM KHAO
11] N. T. H. Gam. Plidt trien iidnfi li/c sdiifi too cho sinh vien thong qua day hoc phdn Hda vo ca \d Li luan • Phuinig phdp day hoc Hoa hoc d trudng Cao dang su phgm.
tdp hai, Luan dn Tien sT Hda hgc. Trirdng Bai hpc SU pham Ha Npi, (2012).
[2] N. Cudng. Thi nghiem thuc hdnh phuong phdp dgy hgc hoa hgc, Nxb Dai hpc SU pham Ha Npi, (2005).
[3] N. N. Quang, N. CUOng, D. X. Trinh, Ly ludn dgy hoc hoa hoc, Nxb Gido dlic. (1982).
[4] Vu giao due trung hpc, Tai lieu hudng ddn dgy hoc thi nghiem thuc hdnh trudng THPT mon Hoa hgc. Bo Giao due va Dao tao (Tai lieu luu hanh npi bp), (2011).
[5] Dir an Viet - Bi, Nghien edu khoa hoe sir pham dng dung. Nxb Dai hoc sir pham Ha Noi, (2010).
[6] Keith W Prichard and R. Melaran Sawyer. Handbook of College teaching-theory and application. Greenwood press, Westporl Conneetial London, (1994).
ENHANCING THE QUALITY OF TEACHING CHEMISTRY AT HIGH SCHOOL BY USING EXPERIMENTS
Ngo Thi Ngoc Mai. Nguyen Thi Kim Anh Chemical experiments play an important role in the development process of human perception of the world, and it is the foundation of teaching chemistry. Experiments are bridges between theory and practice that help students improve their practice skills and their thinking, thus inspiring them to learn chemistty. Chemical experiments are classified into three categories: teachers' performance, students-experiments and real experiments outside the classroom. Eight principles and five methods ean be applied to plan chemistry lessons with experiments. Chemistry practice lessons should be planned in the light of Spickler method to improve students' independence, creativity and sciendfic passion.
'TnrSng THPT chuyen Lc Quy Don, Binh Dinh
"•Khoa Hoa hpc, Trifdng Dai hoc Quy Nhdn
Ngay nhan bii: 05/5/2012; Ngay nhdn dang: 19/12/2012.
