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XAY DUNG VA SUf DUNG HE THONG THI NGHIEM HOA HOC NHAM PHAT TRIEN TUDUY KHOA HOC CHO HOC SINH TRONG DAY HOC HOA HOC 6 T R U O N G TRUNG HOC PHO THONG
TS. CAO IHj THANG - neo Khoa hoc Gliio due Viet Nam ThS. VU MINH TUAN - TiUihig THPT chuydn Trin PhD, m Phing I . D a t v a n d l
Td duy khoa hpe Id mdt phim chat d n t h i l t cho ngddi lao ddng trong b i t ki thdi dai n i o nhat la trong t h i gidi day biln ddng hien nay.Tu duy khoa hpc dupe phit trien ngay khi hpe sinh (HS) dang hpc t i p d trudng phd thdng nhat 11 d Trung hpe phd thdng (THPT). TU duy khoa hoc ddpc phit triln eho HS thdng qua d e mdn hpc khie nhau trong dd phli k l d i n d e mdn khoa hpe tu nhiln, die b i l t Id mdn Hda hpc Llm t h i n i o de phdt triln tuduy khoa hpc hda hpc la mdt v i n de d l v l ludn dupe d l t ra trong day hpe hda hoe.
Thf nghiim hda hgc c6 mpt vai trd quan trgng trong dgy hgc tfch cue bp mdn Hda hoc vd ddc biit trong viic phdt trien tuduy khoa hgc cho HS. Theo chung toi, khic vdi d e h dgy I p dgt, thdng bdo cho HS v l tfnh chat hda hpc da bilt v l ddng t^c thi nghiem d l minh hpa, cich dgy hpe tfeh eUc gidp phat trien t d duy khoa hpe khi nghiln cdu tfnh chit hda hpc eua d e don ehat, hpp ehit vd CO v l hdu ea theo mdt quy trinh 5 bdde I I : Bude 1:
Gido viin (GV) niu vin dicdn tim hiiu; BUdc 2: GVyeu edu HS du dodn niu gid thuyit vi tinh chit cda chit, loai chit cdn tim hiiu; BUdc 3: GVyiu eau HS kiem tra dtf dodn bdng thf nghiim; Budc 4: HS tiin hdnh thf nghiim, ghi kit qud thf nghiim; Budc 5: HS rut ra kit ludn vi tfnh chit hda hgc ttf kit qud thf nghiim.
Qui trinh sd dyng thf nghiim day hpc theo 5 budc trln giiip HS phdt triln tU duy khoa hpc: nly sinh van 64 d n tlm hieu, dy doln ddpc tinh chit hda hoc cda chit edn ed vao tinh chit chung cda loai ehit, d u tgo phln td cda ehat, hda trj/sd oxi hda cua chit... HS ddpc phdt triln mdt sd kT nlng t u duy khoa hpc nhu phit hien v i n 64, n l u dy doan/gil thuyet kilm tra dd doln blng thue nghi$m (phln tfeh, tdng hop, lien tudng, ey t h i hda, khii quit hda, quan sit, md t l , gidi thich), rdt ra k i t luan ve tfnh chit hda hpc cda mdt loai ehit hay mdt chat cy t h i , mdtquylugt...
Ngoli cde thf nghiim hda hpe d l ddpc n l u trong sdch gido khoa, sich GV, sleh hudng d i n sd dung t h i l t bj, thf nghiem hda hoc, mdt sd loai thi nghiem hda hoe cin ddpc xay dung v l sddyng hop li trong q u i trinh dgy hpe tfeh cde mdn Hda hpc. Cin ed vdo cleh sddyng thf nghiim hda hpc trong day hpe tfeh cue, ehung tdi 64 xult cleh p h l n logi nhU sau:
- m nghiim nghiin ctfu: Cac thi nghiim hda hpc do GV hoac nhdm HS thdc hiln nhim rdt ra tinh chit hda hpc mcri cda ehit hode tim tdi ra mdt van 64 mdi lien quan d i n hda hpc ndi chung;
- Thf nghiim klim chtfng: Cle thf nghiem hda hpc ddpc GV hode nhdm HS sddyng 6i kilm chdng cho mdt g i l thuylt hialc mdt dy dodn cd t h i xly ra nhd: tinh chit cda ehit, phdong phip dilu ehl mdt chit, mdt quy trinh
xd lichat t h i i . . . ;
- Thf nghiem so sdnh dii chiiu: Cip thf nghiim hda hpc dUde GV hode nhdm HS sd dung nhim so sanh, ddi chieu cho thay rd tie dyng eua d e chit cu t h i vdi edng mdt loai ehit d l cd the cd khdi quit hda day du v l mdt van 64 nghiln edu;
- Thi nghiim niu van de: Thdng qua t i l n hlnh mdt thf nghiim ey t h i , GV hode HS llm nly sinh van de d n nghiln edu;
-Thi nghiim gidl quyet vin di: Khi CO tinh hudng van 64 xuat hidn, cd t h i sd dung thf nghlgm 6i gili quyet van 64 theo d c dy dodn/gil thuylt khoa hpc d l xuit khic nhau.
Cac logi thf nghiem trdn ed sd khic bilt rd r i t khi sd dyng de phit triln t d duy khoa hpe eho HS so vdi loai thi nghiim ehi nhim myc dfch minh hpa eho dilu da dupe khIng djnh.
O l sd dung cle thf nghiem dd d n phli bilt xly ddng d e thf nghiim theo myc dfch day hpe hda hpe phu h ^ vdi mdi ndi dung eu t h i . Sau ddy Id mdt sd vf du v l xly ddng v l sd dung thf nghiim 64 phdt triln t u duy khoa hpe eho HS trong q u i trinh day hpe tieh eUe bd mdn Hda hpc
2. X l y dung v l stf dung thf n g h i i m kiem chuTng v l rut ra ket l u i n v l tinh chat hda hoc
Trong nhieu trudng hop 64 phdt trien t u duy khoa hpe, GV can tao dilu ki^n de HS ed t h i t i l n hlnh mdt sd thi nghiem d l kilm tra dddoan cda minh theo quy trinh;
Dd doan - » Kiem tra blng thi nghiim hda hpe -> Kit luan v l tfnh chit cda chat.
Vidu: Khi nghiln cdu tinh chit hda hpe eda oxi cd t h i thdc hiln theo quy trinh sau:
- HS d u d o l n tlnh ehat hda hpe eda oxi: Oxi cd dp dm dlln Idp chl sau flo, nguyin td oxi cd clu hlnh electron Id 1s^2s^2p*, cd 6e d Idp ngoai eung nln de ding nhln t h l m 2e d l trd thlnh d u hlnh b i t td b i n vdng. Do dd, oxi ed t h i II chit oxi hda mgnh v l t h i hiln tinh phi kim cd the Id mgnh. Phln t d oxi ed lien kit ddi tdong ddi ben vdng, do dd oxi ehl t h i hiln tfnh chit nly d dilu kiln nhat dinh.
Tuy nhien, trong khoa hpc moi dd doan van II dd doln, ehdng ta d n kiem tra dd doln ndy.
- HS kilm tra dydoan blng thf nghiim kiem chdng:
De kilm tra tfnh oxi hda manh d nhiet dp eao, d n t h i l t cho HS nghiln edu thf nghiim d nhilt dp thddng va sau dd mcri cung d p nhilt dd cho phln dng. Vgy d n phli cd nhdng thi nghiem ndo? GV cd t h i xay ddng d c thf nghiem sau:
Cho oxi phln dng vdi kim loai mgnh, trung blnh, ylu: nhdm, sit, ddng... Oxi phln dng vdi phi kim cd dd boat ddng khic nhau: S, C, R.. Oxi phln dng vdi mdt sd
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O l kilm ehdng tfnh phi kim mgnh cua oxi, d n kilm tra mde dd phln dng eua oxi vdi kim logi v l vdi hidro.
Do dd, ngoli eae thf nghiem t r l n , d n xay dung them thf nghiim oxi phdn dng vdi hidro, phan dng d dieu kien thudng v l d nhiet do eao. Nhutig thi nghiem nay thuc hiln 6 nhilt dp thudng trddc sau dd dot ndng hole chim Ida de HS thay rd dilu kiln d l phln dng thUc hiln ddpc: d n eung d p mdt nhiet dd nhlt djnh th) phln dng mdi xly ra.
HS viet phuong trinh hda hpe (PTHH) cua d e phln dng oxi hda khd trln de t h i y ring trong d e phln dng:
Nguyin td oxi ludn nhln 2e va sd oxi hda eua oxi trong d c hpp chit d l u II -2.
Td d c thf nghiim v l d c PTHH phln dng oxi hda - khd, k i t hpp thi nghiem kiem ehdng va d nhdng thf dy ma HS dd bilt t d Idp 8, Idp 9 vd dau Idp 10, HS rdt ra ddpc kit tudn nhu sau: Oxi oxi hda dupe rat nhieu don ehit v l hop chit, oxi oxi hda dupc hau h i t ede kim loai vd hidro d nhilt dd cao. Oxi cd tfnh oxi hda mgnh va Id phi kim hoat ddng manh d nhilt dd cao.
Nhd vgy, HS hoan t o l n cd t h i dpc lap nghiln edu tfnh chit hda hpe cda oxi theo quy trinh khoa hpc va gidp phit triln tu duy khoa hpe d Idp 10.
3. X l y dung v l stf dung thi nghiem gidp HS so sinh, ddi chieu rdt ra tfnh ch^t hda hoc cCia chat theo quytrlnh khoa hpc
Cd r i t nhilu tfnh ehat ehung cda d c loai chat dPn ehit, hpp chit d n dupe hlnh thdnh de HS cd mdt khii qudt ehung v l tfnh chit cda chung.Tuy nhien, trong mdi loai don chit vd hpp ehat do khdng phli mpi ehat ey the d l u ed tfnh chit gidng nhau hodn t o l n m l gida ehung cung ed tinh chit rilng khie nhau do d u tao nguyin td, d u tao phdn td, thdnh phln nguyin td khae nhau.
Do dd, d l hlnh thanh khdi nilm tinh chit cua chat d n sd dyng thi nghiem ddi ehdng d l HS cd the thay ddoe sU khde biet dd.
Vf du: O l nghien edu tfnh chit eua HNO^ die ta can xdy dung d c cap thf nghiim ddi chdng: HNO^ dgc tdc dung vdi Cu, HNO^ dde phdn dng vdi AI (Fe) d nhiet dp thddng v l khi dun ndng. Qua thf nghiim, HS nit ra k i t ludn ring: HNO^ dgc ngudi oxi hda dupe nhieu kim loai trd AI, Fe, Cr, HNO, dae ndng oxi hda dupe hau bet cae kim logi.
D l nghien edu phln dng eda kim loai vi^ mudi cung d n xly dyng eae d p thi nghiem ddi ehdng d l HS rdt ra d i l u kiln cda phdn dng mdt cleh ed eo sd khoa hpc. Thi du cap thi nghiim ddi ehdng: Cu t i e dung vdi dung dich AgNOj v l Cu t i e dyng vdi dung djch ZnCI^...
Td kit q u i thi nghiem, HS cd the xac cfinh sin pham v l vilt PTHH phln dng oxi hda - khd, rut ra kit luan ring:
Kim loai cd the d i l n cdc ehuan nhd hem cd t h i khddupe ion kim loai cd the dien cdc chuan eao ban trong dung dieh mudi.
O l thay rd vai trd t i e nhdn oxi hda v l mde dp oxi hda eua axit H^SO^ loang va H SO^ dgc ehiing ta xly dyng va sddyng elp thf nghiem ddi chdng: Cho axit H^SO^ loang v l H,50^ die d l u phln dng vdi sit d nhilt dp thudng vd dun ndng.Td hi|n tUcmg thf nghiem v l cic phuong trinh phln dng oxi hda khd, HS nit ra k i t luan:Tinh oxi hda cua HjSO^ loang do chu y l u ion H* quylt djnh, tfnh oxi hda
manh eua H^SO dgc (ndng) do ehu y l u S cd sd oxi hda +6 trong ion SO/- quylt dinh (thdc ra II d phdn t d H SO quylt djnh). H^SO^ die cd tinh oxi hda manh nen da oxi hda Fe thlnh ion Fe^ (dung djch Fe,SOJj ed mlu vdng ndu), cdn ion H* trong dung djch H^SO^ loang cd tfnh oxi hda yeu ban n l n da oxi hda Fe thlnh ion Fe** (dung dich FeSO^ ed khdng mdu (hode luc nhat n l u ndng dd eao).
4. Xay dOng vk stf dung thf nghiim d l g i i i quyet vin Si n h i m p h i t trien tUduy khoa hoc cho HS
Gili quylt v i n d l trong day hpc hda hpe giiip phdt trien nang ldc sing tao, tich ede, ndng lyc ldm vile hpp t i e eho HS v l gdp phan quan trpng phdt triln tU duy khoa hpc eho HS.Trong day hpc hda hpe dTHPTcung cd nhilu CO hdi cd t h i sd dyng thi nghiim theo hddng ndy.
Vfdu.Van 64 dat ra khi thdc hiln phln dng ddt chly chat hdu cO: Ddt ehly khf metan, dUdng gluco, ddt ehdy bdng, ddt chly ancol etylie... Ii|u ed tgo ra sin phim gidng nhau khdng? O l gili quylt v i n d l ndy can nlu ra d e g i l thuyet/du doln sau:
Dd doln 1: Sin pham chly eCla ehung deu gidng nhau: tgo thdnh khi cacbonlc vd ndde;
Dd doln 2: Sin pham ehly cOa chiing cd t h i gidng nhau, nhdng cd t h i cdn cd sin phim khic Cin xly dyng thf nghiim gili quylt van de tren: Thyc hi^n phdn dng ddt ehly vd kilm chdng sin phim phln dng.
-Thf nghiem 1:Ddt ehdy tdng ehit blng edeh ehdm Ida hole ddt ndng.
- Thi nghiim 2: Kilm ehdng sin phim phln dng:
xlc djnh cd hoi ndde b i m vdo thlnh dng nghiim ho^c ldm md tam kfnh hay khdng?
Xlc djnh khf CO, blng cleh din khf tao thlnh sgc vao blnh dung nude vdi trong.
Ngodi ra, cd t h i quan sdt thlm: cd mlu den xult hiln d thlnh dng nghlfm hode d b l mat t l m kfnh (d^t trdn ngpn Ida). HS d n t i l n hlnh thf nghiim, quan sdt, md td hien tuang, g i l i thfch vd rut ra k i t ludn: Gid thuylt 1 hay g i l thuylt 2 II ddng?
Thue t l eho thay, g i l thuylt 2 ed t h i dung vl sdn pham edn cd than (cacbon). Nhd viy, d n sd dyng thi nghiim tren thi mdi gili quylt dupe v i n d l d l t ra.
Chdng tdi da d l xult quy trlnh xly dUng v l sddyng thf nghiim theo hddng phdt triln t u duy khoa hoc cin thye hiln theo quy trinh sau:
Bude 1: GV nghiln cdu mye ti§u bdi hpe theo chuin kiln thdc kT nang eda ehdong, b l i cu t h i hole phdn tich ede van 64 d n gili quylt;
Bude 2: GV du kiln d c dd doln hole gid thuyet khae nhau;
Bdde 3: GV thiet k l / x l y dUng cle thi nghiim kilm ehdng, thi nghiim ddi ehdng, thf nghif m gili quylt vin 64 nhim giup HS kiem tra g i l thuylt/ dU doln dung, tao dilu kiln HS tim tdi xay dung kiln thdc mdi v l phit triln tuduy khoa hoc cho HS;
BUdc4:GVsddyng d e thi nghiim trln theo hddng t6 chdc d l HS dupe lam vile ddc sing tgo nhim phit triln tU duy khoa hpe theo tdng bdi ehucmg phln cy t h i cho phii hpp.
Bdng sau d l y (Xem blng d trang 61 )nhd I I mdt g^l y giup GV thiet ke thf nghiem hda hpe phu hpp d l phdt trien t d duy khoa hpc:
(Xem tiip trang 61) 22 -KHOAHpcGU^DSyC
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nhau d l dieu chinh elch hpc kip thdL Can luu y eho HS v l kT ndng, t h i i dp khi dinh g i i eho ban nhu can trung thUe, thing t h i n , nhe nhing, khdng nen ehl bai, de blu, tgo t l m If nang n l eho ngudi dUOc dinh gia. Thdng qua dd, HS ed the biet tU dilu chlnh deh ldm viee nhdm v l xem lai viee phln edng val trd cda tiing ngudi trong nhdm, tddd rdt ra bdi hpe kinh nghiim 64 vile thuc hiln cde nhlfm vu t i l p theo duac tdt hdn.
4. K i t luan
Nlng eao nang luc hpp tie thdng qua boat ddng hpc tap d Idp ghep ddng vai trd quan trpng trong vile ndng cao ehat lupng gilo dye t i l u hpc vung d i n tdc v l miln nui. Day HS hpc hpp tde theo nhdm trinh dd d ldp ghIp gidp mdi HS d i n tde elm t h i y ddpc tdn trpng.
Dilu nly s§ khuyin khfch, thdc day d e em hpc tap mdt deh tich cue, duy tri ddng Ide hpe eho HS d i n toe thilu sd v l giiip cie em nlng cao trdch nhiem eda minh ddi vdi vi$c hpe. Khi dupe hpc t i p hpp tic, elc em se ed t h i i dd tfeh cue trong hoc t i p , nlng cao Idng t u trpng vd tdn trpng bgn trong nhdm cung trtnh dd, gilm khodng d e h gida nhdng HS hoe khi v l HS hpc y l u hon. Thdng qua hoat ddng hpc hpp t i e theo nhdm, HS phat triln d c kT ndng khic nhau, trong dd die bilt quan trpng la kT nlng Ilm vile va hpe tap trong mdi trUdng tap the. Ddng thdi, qua hoc t i p hc^ t i c trong nhdm, kT ndng thuyet phuc, kT ndng Ung nghe tfch cUc, kT nlng td ehde, ki nang cHlu khiln vd llnh dgo dupe rln luyen va phat trien. Hieu q u i Idn nhlt eda hoc tap hpp t i c trong nhdm d Ic^ ghep II HS trd thdnh nhdng thdnh viln tieh eye, ndng ddng, sin sing hpp tic vdi ban 64 thde hlln tdt cle nhilm vu d l t ra. HS ed y thde td chdc, tinh t h i n tUOng trp lan nhau
trong mpi hogt ddng gilo dye se trd thlnh nhdng HS ehd dpng, sang tao, biet hpp t i e phu hpp vdi y l u cau phat trien nlng lue hpp t i e trong ehdong trtnh giao dye d p Tilu hpc hiln nay.
TAILIIUTHAMKHAO
[1]. Bd Giao dye va Ddo tao, (2014), Chuang trinh tong the gido due pho thdng.
[2]. Ddan Gido ducTieu hpe Bgn hdu t r l em, (2002), Dgy hge ldp ghep hiiu qud.
[3]. Du an Phat triln Gido viln t i l u hoc (2007), Dpy hge ldp ghep.
[4]. Dd an Giao due Tilu hpe eho tre em cd hodn cinh khd khan, (2010), Dgy hgc ldp ghip 2 trinh dp.
[5]. Gido due ldp ghip vd song ngtf d trudng tiiu hgc Viet Nam, Tdl lilu bdi dudng d n bd, giao vien tieu hoc, NXB Giao due 2000.
SUMMARY
Multigrade classroom is a speeific class in ethnic education and will exist regularly in ethnic minority and mountainous areas, its key activity is to study in groups at the same level.Thus,the formation and developmentofstudents' collaborative competence through educational activities in general, learning activity in particular plays an important role, contributes to improving quality of education, meets requirements of primary education program after 2015.
Keywords: Collaborative competence; multigrade classroom; pupils.
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XAY DUNG VA SU DUNG HE THONG THI NGHIEM...
(Tiep theo trang 22) Tin billn6i dung Cic thi nghifm cuthi
Djnh hudng sddung (Thf nghiim kilm didng, thi nghi§m dS chdng, thf nghiem
nlii v l gill quyA vin de_) H6a chit, dung cu..
5. Ket luan
Trong q u i trtnh day hpc theo cleh t r l n eho HS, da ehdng td: Vile sd dyng thi nghiim theo hudng tfeh cue, linh hoat sang tgo giiip eho HS phdt trien dupe tU duy khoa hpe. Bdi vl, mpi ket lugn trong qud trinh dgy hpc mdn Hda hpc dupe rut ra d l u dda trln nhdng blng ehdng khoa hpc rd rang, ddy dO thdng qua k i t q u i cua cdc thi nghiem hda hpc kilm ehdng dupe gil thuyet/du dodn ddng.
TAILIIUTHAMKHAO
[1 ]. Cao Thi Thang (ehd biln), (2008), Mpt so van de ail mdi phuang phdp dgy hge hda hgc d trudng trung hoc casd, NXB Gilo due HI Ndi.
[21. Trln Ba Hodnh, Cao Thi Thang, Pham Lan Huong, (2003), Ap dung dgy hgc tfch cue trong mon Hda hgc d trung hgc ca sd vd mdn Khoa hgc dTieu hgc, NXR Oai hpe Sd phgm, Hd Ndi.
[3]. Nguyen Lang Blnh, Dd Hdong Trd, Nguyen Phuong Hdng, Cao Thj Thing, (2010), Dgy vd hgc tfch ctfc - Phuang phdp vd ki thudt day hgc, UXB Dai hgc Supham, HI Ndi.
[4]. Cao Thj Thdng, (2010), Nghien ctfu, thiit ki cdu hdi vd bdi tdp ddnh gid kit qud hge tdp theo chudn kiin thtfe, ki ndng mdn Hda hge (chuang trinh gido due phS thdng), Tgp ehf Gido dye, sd 230, tr. 41 - 43.
[5]. Cao Thi Thang, (2009), Stf dung thi nghiem detich ctfc hda hogt dpng hgc tdp Hda hoc d Tieu hgc. Trung hoc ca sd vd cao ddng sUphgm, Tap chf Thilt bj Gilo due, sd 51,tr. 15-17.
SUMMARY
Scientifie thinking is an essential quality for workers in any society especially in current changing context.
Scientific thinking is developed for students through different subjects including Chemistry. How to develop scientifie thinking in Chemistry is an urgent issue in Chemistry teaching. The article provides information on building and using Chemistry experimental system in order to develop students' scientific thinking at high schools.
Keyvmrds: Scientifie thinking; Chemistry experiment;
Chemistry.
Stfl18-THJillfi7/2giS-6l
