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K600T ThS.NGUYEN DINH DO GIAI Q U Y E T NHA XUAT B A N D A I HOC QUOC GIA HA NOI THS.NGUYIN DilMH DO GIAI Q U Y E T NHANH GON DE THI D A I HOC mon THI/ ViEN TJNHBIMH TMUAN Ha Npi NHA XUAT BAN DAI HOC QUOC GIA HA NQI Cac em hoc s i n h t h a n men De l a m t o t bai t h i D a i hoc la mong muon cua t a t ca cac em t r o n g cac mua t h i Doi v(5i m o n Hoa, day l a i la v a n de bijfc thiet I d n , v i le n o i dung de t h i Hoa t r a i dai ca ba k h o i 10; 11; 12 k h i e n k l i o i lifgrng k i e n thijfc di/cfng n h i i la ca mot b i e n trofi m e n h mong, vo t a n That ra, Hoa hoc la m o n hoc r a t nhe n h a n g ne'u cae em biet hoc c6 phqo'ng phap, v i le t a t ca phan ufng hoa hoc hay t i n h chat hoa hoc cua cac chat deu dUofc xac d i n h thee cac qui luat Do v a n de la n a m dtfOc cac qui luat t h i t a deu c6 the de dang diT doan t i n h chat hoa hoc m o t chat, hay de dang viet r a san pham phan ijfng giffa cac chat m a k h o n g can phai hoc thuoc san p h a m nhir cac em l a m tiio'ng bay lau N o i khac d i , hoc Hoa khong can phai hoc thuoc long, k h o n g can p h a i nhcr n h i e u nhiJng dieu ma chi can qua suy luan c6 the de dang n h a n r a chung (chang h a n t r o n g mot nhom A k h i d i tCf t r e n xuong difdi t h i ban k i n h nguyen tii" cac nguyen to bat buoc phai tang dan, do'n gian v i so Idp electron cua nguyen tuf cac nguyen to tang dan) Nguyen tSc hoc Hoa la the, vay neu k h o n g c6 k y t h u a t l a m b a i t h i trac nghiem khach quan t h i diem so' se k h o n g n h i i y so v(5i thiic life Do la thifc te ma bat cuf hoc sinh nao cung c6 the n h a n ra, va day c h i n h la l y ddi ciia tap sach Chuc cac em t i m thay n i e m vui t r o n g hoc tap, va n h a t la p h a i dat diftfc ket qua m y m a n n h a t t r o n g t h i cuf Tac gia Nguyin Dlnh 06 O CHLTdNG I KY THa6T Gl^l DE THI TR^C NGHIEM Mot dieu khong the phu nhan la du ndm rat chSc cac k i e n thijTc sach giao khoa, nhieu t h i sinh vSn khong the giai quyet t r o n ven cac cau hoi cac de t h i Dai hoc Mot thqc te la da so cac cau trSc nghiem ly thuyet cung nhif bai tap ma t h i sinh xem la rSc r o i , d i bi mat diem cac de t h i , hoac cac cau ma t h i sinh mii mcr hay ma ho ve hqdng giai l a i c6 the giai quyet rat tot bang phtfang phap loai triT Vay the nao la phqang phap loai trif? De de h i n h dung, h-ay xem mot v i du sau khong lien quan den Hoa hoc: Trong so cac nhiem ky long thong My tie xUa den nay, vi tong thong nhdt doc than den cud'i dai Id: A Bill Clinton B Jone F C James Buchanan D Abraham Kennedy Lincoln Dap an dung cho cau hoi t r e n la C (James Buchanan) Nhiftig ro rang, cau tra Idi khong phai xuat phat iii sii hieu biet ve than the James Buchanan, vi v i tong thong thijf 15 ciia Hop chung quoc Hoa ky la mot ten tuoi kha xa la vdri chung ta Cach lam d day la dung phqang phap loai trif: Trifdc tien loai triT B i l l Clinton v i han chiing t a nh6 hai vg chong tong thong B i l l Clinton ti/ng CO chuyen ghe tham Viet Nam (nam 2000) Tiep theo, tong thong Jone F Kennedy cung nam danh sach loai trii, vi vu am sat ong vao nam 1963 tai pho' Dallas, tieu bang Texas k h i dang cung phu nhan t h a m vieng tieu bang nay, la mot sii kien chan dong the gidi thcfi va hien c6 le khong khong biet Cuo'i cung, loai trCf not Abraham Lincoln cupc hon nhan day bait hanh ciia v i tong thong da dqcfc ghi l a i qua kha nhieu giai thoai Ro rang James Buchanan phai la sii liia chon cuo'i cung! Chung ta tiep tuc xem mot v i du c6 le gan gui hon v i du tren, va van la mot v i du khong lien quan den Hoa hoc: Hoa iCac Gidp Than hay c6 ten Hoa uac Patenotre (Pa-ta-not), Id hoa Udc cuo'i Cling nha Nguyen ky vai thuc dan Phap Hoa Uac Gidp Than dugc ky vdo nam ndo ditai day? A 194S B 1789 C 1752 D 1884 Khong dijng cong thufc doi nam duong lich sang nam am lich, ro rang phai loai trii nam 1948, v i trieu dai riEa Nguy§n ket thuc k h i vua Bao D a i tuyen bo' thoai v i , trao an kie'm cho dai dien chinh phu Viet nam dan chii cong hoa vao nam 1945 Cung nhanh chong loai trii nam 1789, v i day la nam vua Quang Trung keo quan Thang Long tieu diet quan Thanh Luc trieu dai nha N g u y i n chtfa diigc t.hie't lap, v i chi k h i Anh mcri x L f n g ngoi vua, lay nien hieu N g u y i n Hoan toan ttfctng t i i n h i f tren, N g u y i n chi c6 the bat dau tCf sau nam nien hieu Gia Long nam 1802) danh bai ducfc nha Tay Scfn, la Gia Long, md dau trieu loai trCr nSm 1752, v i trieu 1789 (Nguyen Anh len ngoi Nguyen dai nha dai nha vua, lay Vay liia chon cuo'i cung phai la D (nam 1884) Bay gid, ta bat tay vao mot v i du thuoc ve l i n h vifc Hoa hoc: Co ancol sau: CH3OH (I); CH3CH2CH2OH (II); CHsCmCHsJOH (III) TM tu tang dan nhiet soi cda ancol tren theo chieu til trdi sang phdi la: A (II); (I); (III) B (I); (III); (II) C (II); (III); (I) D (Ill); (I); (II) Se CO rat nhieu h o c sinh lung tung k h i doc v i du tren, sach giao khoa hoan toan khong de cap den nhiet s o i cua ancol dong phan, cu the d day la cac ancol C H C H C H O H va CH3CH(CH3)OH Tuy vay de dang nhan phai loai trCf A (ancol I C k h o n g the c6 n h i e t soi cao h a n ancol 3C); Cung l i do, phai loai trCr C va D, nen nhanh chong t i m dtfcJc dap an dung la B (thUc te nhiet soi cua ancol C H O H ; C H C H C H O H ; C H C H ( C H ) O H Ian luat la 64,7°C; 97,2°C va 82,3°C) Vf du sau day la mot dien hinh ro net cho viec sijf dung phucfng phap loai tni: Cho bot Fe vdo dung dich gSm AgNOs vd Cu(N03)2 Sau cac phan ring xdy hoan toan, thu dugc dung dich X gom hai mudi vd chat rdn Y gom hai kim loai Hai muoi X vd hai kim loai Y Idn lilat Id: D Cu(N03)2; AgNOg va Cu; Ag C Fe(N03)2; Fe(N03)3 va Cu; Ag B Cu(N03)2; Fe(N03)2 va Ag; Cu A Cu(N03)2; Fe(N03)2 va Cu; Fe (Dai hoc 2013 khoi A) Khong mat nhieu thcfi gian de nhan dap an can t i m la B That vay, ta loai trii A, v i Fe t r o n g Y phai tac dung vdi Cu(N03)2 t r o n g X nen sau phan ufng khong the thu difac nhOfng chat nhtf the; tiicrng tii la loai triT C vi Cu t r o n g Y phai tac dung vdi Fe(N03)3 t r o n g X, va cuoi cung loai trCr D vi Cu t r o n g Y phai tac dung vdi AgN03 t r o n g X Ro r a n g phifcfng phap loai triT hgp da to r o tfu the t r o n g giai trac nghiem! t r o n g trLfcfng Can biet them rang phifcfng phap loai tnlf khong phai chi dimg cho cac cau trac nghiem ly thuyet Trong mot so' bai toan ma hudng di mu mcJ, chiia the dinh h i n h t h i phucfng phap loai trif cung g i u p ta loai bo cac phifong an sai, ti^ xac dinh diicfc dap an ciia bai toan Cac em hay quan sat v i du sau: Hoa tan hodn todn m gam Al bdng dung dich HNO3 lodng, thu dugc 5,376 lit (dktc) hSn hgp X gom N2, N2O vd dung dich chiia 8m gam mudi Tl khoi cua X so vdi H2 bdng 18 Gia tri cua m Id A 17,28 B 19,44 C 18,90 D 21,60 (Dai hpc 2013 - khoi A) r Rat nhieu hoc sink nhanh chong xdc dinh dugc buac ddu tien d ddy la phdi tim so mol tilng Do Id huang di diing! Theo dU kien dd cho, ta cd so mol N2 = so mol NoO = 0,12 mol Tuy nhien huang di tiep ddi vdi mot so em cd the Id chua ro rang, dd ta dung philang phdp loai triC: Be y rdng tong so mol electron md N*^ dd nhan de too N2 vd NoO = 0,12.10 + 0,12.8 = 2,16 mol, do: 17 28 - Loai tril A, vi neu chon m = 17,28 thi nAi -—'— = 0,64 mol Khi dd 27 rieiectron Ai cho = 0,64.3 = 1,92 mol < 2,16 mol 18 90 — • Loai trii C, vi neu chon m = 18,90 thi nAi =—'—0,70 mol Khi dd 27 neiectron Ai cho = 0,70.3 = 2,10 mol < 2,16 mol 19 44 - Loai trie B, vi neu chon m = 19,44 thi UAI =— = 0,72 mol.Khi dd 2.1 n-eiectron doAi cho = 0,72.3 = 2,16 chitng to khdng tgo NH4NO3 Do dd rn.,nu6i = rn + 62(10.0,12 + 8.0,12) ^ 8m m - 19,13-^19,44 Vdy chon D Cdch khdc Nhif tren da noi, ta chi dung phuang phap loai triT k h i hiTdrng giai bai toan mcf ho, chifa xac dinh Neu da n&m dtfcfc phiicfng phap giai toan ve k i m loai tac dung vori H N O a , bai n a y di/gc giai theo bao toan electron nhuf sau: Ta cd so mol N2 = sd mol N2O = 0,12 mol Gid sit mud'i ihu diigc gom ~ mol AKNOsJs vd x mol NH4NO3 27 + x - m x = 720 T a c d 213 — Bao todn electron cho — = 0,12.10 + 0,12.8 + - ^ « 11 720 m = 21,6 Hoac v i du sau t h i phi/ang phap loai trCf the h i e n ro lAi diem giai trac nghiem: Hidro hda hodn todn 0,025 mol hdn hgp X gom hai andehit can 1,12 lit H2 (dkc) Mat khdc, cho cung lUgng X tren phdn ling vdi mot lUgng dU dung dich AgNOs NH3 thi thu dugc 8,64 gam Ag Cong thiCc can tgo cda hai andehit X Id: A OHC-CH2-CHO B H-CHO vd vd OHC- OHC-CH2-CHO CH2-CH2CHO C C H s C - C H O vd D CH2=CH-CH0 vd OHCCH2-CHO OHC-CHO Gidi Ta CO so lien ket n truns "H 0,05 binh = — ^ = — = nen loai trie B, C "KK 0,025 hh ' Mat khdc so mol Ag = 0,08 tiic ux •' nAg = : 3,2 nen phdi loai tril A Yqy chon D D i e u dac b i e t l a d nhCfng cau l y t h u y e t h a y b a i t o a n m a dcr l i e u da cho l a k h o n g d a y d u t h i phifcfng p h a p l o a i t n f t o r o l a m o t sir l i i a chon t o i UU T h a t vay, t a x e t v i d u sau: X la chat hOu ca tdc dung vai Na diC cho so mol H2 bay b&ng so mol NaOH can diing de trung hba het cUng luang X tren Cong thiCc phan tit cila X Id A C4H8O2 C C7H12O2 B CeHi403 D CgHioOz De d a n g loai trtr B v i CGHMOS k h o n g p h a n tfng di/oc vcri N a O H Cung loai tvii A, C v i C4H8O2 v a C7H12O2 g i a i phong so m o l H2 = — so m o l N a O H Vdy chon D Hoac a v i d u sau, c6 v6 so' h n h o p ancol t h o a m a n de b a i n e n n e u sa da vao g i a thie't se k h o n g t h e c6 k e t qua: Cho hon hap X gom hai ancol Dot chdy hodn todn 0,3 mol hSn hap X thu dugc 22 gam CO2 Mat khdc 0,3 mol X tdc dung vai Na dU diiac 5,6 lit H2 (dkc) Hai ancol dd cho Id: A CH3OH vd C2H5OH C C2H/OH)2 B CH3OH vd C3HdOH)2 D CH3OH vd C3H6(OH)2 vd C3H5(OH)3 T a l o a i t r i f n g a y A , B v a C h n h o p c6 so C t r u n g b i n h = so' n h o m O H = 1,66 V a y c h o n D , tufc ancol t r e n l a C H O H v a C3H5(OH)3 trung binh - ^ B A I TAP AP D U N G Cho b o t M g va Fe vao d u n g d i c h g o m A g N v a Cu(N03)2 Sau k h i cac p h a n ufng x a y r a h o a n t o a n , t h u difcfc d u n g dich X g o m b a m u o i v a c h a t r a n Y g o m h a i k i m l o a i B a m u o i t r o n g X v a h a i k i m l o a i t r o n g Y I a n li/cft l a : A M g ( N ) ; Fe(N03)2; F e ( N ) v a Fe; Cu B Cu(N03)2; A g N O s ; F e ( N ) v a A g ; Cu C M g ( N ) ; F e ( N ) ; Cu(N03)2 v a A g ; Cu D Mg(N03)2; Fe(N03)2; Cu(N03)2 v a A g ; Cu Gidi Ro rang dap an can tim Id D That vdy, ta loai trit A, vi Fe vd Cu Y phdi tdc dung vai FefNOsJs X nen sau phdn ring khong the thu dugc nhQng chat nhii the; tuang tu Id loai trie B vi Cu Y phdi tdc dung vai FefNOsJs vd AgNOs X, vd cuoi cung loai trit C vi Cu Y phdi tdc dung vai Fe(N0s)3 X Vdy chon D C h o h o n hcfp g o m F e v a M g v a o d u n g d i c h A g N O a , k h i c a c p h a n uTng x a y r a h o a n t o a n t h u diicfc d u n g d i c h X ( g o m h a i muo'i) v a c h a t rfin Y ( g o m h a i k i m loai) H a i muoi t r o n g X l a : A Mg(N03)2 v a Fe(N03)2 B Fe(N03)2 v a AgNOa C Fe(N03)3 v a Mg(N03)2 ' D AgNOg v a Mg(N03)^_ Gidi Chu y rdng rdn Y d day Id Ag vd Fe (dang bdi tap cho hdn hap kim loai vdo dung dich gom hdn hap cdc muoi thi rdn thu dugc phdi Uu tien Id cdc kim loai CO tinh khit yeu nhdt) Do di ddng loai trii cdc phitang dn B, C, D vd lua chon dap dn A Vdy chon A T h i n g h i e m n a o s a u d a y chufng to t r o n g p h a n tuf glucozcf c6 n h o m h i d r o x y l ? A Khijf h o a n t o a n glucozcf t h a n h h e x a n B C h o glucozcf t a c d u n g vdri C u ( O H ) C T i e n h a n h p h a n ufng t a o e s t e c i i a g l u c o z a vdri a n h i d r i t a x e t i c D T h i f c h i e n p h a n ufng t r a n g b a c Gidi Loai trie A vi day Id thi nghiem de chiing minh phdn td glucoza c6 6C khong phdn nhdnh Loai trii B vi ddy la thi nghiem de chiing minh phdn tit glucoza c6 cdc nhom OH ditng ke Loai triiD vi ddy la thi nghiem de chitng minh phdn tic glucoza c6 nhom -CHO Vdy chon C C h o p h a n ijfng : N ( k ) + H ( k ) < > 2NH3 ( k ) ; AH = -92 k J H a i bien phap deu l a m c a n b a n g c h u y e n d i c h theo c h i e u t h u a n l a A g i a m n h i e t v a g i a m a p s u a t B t a n g n h i e t v a t a n g a p s u a t C g i a m n h i e t v a t a n g ^p s u a t D t a n g n h i e t v a g i a m a p s u a t Gidi Loai trii A vi gidm dp suat thi can bdng se chuyen dich theo chieu Loai trie B, D vi tang nhiet dp thi can bdng se chuyen dich theo chieu nghich nghich Vdy chon C Cho phircfng t r i n h hoa hoc: 2X + 2NaOH > 2CH4 + K2CO3 + NagCOg Chat X la A CH2(COOK)2 B CH2(COONa)2 C C H C O O K D CHgCOONa Gidi Loai trii A, B vi khong bdo tocin H a ve Loai trii D vi Xphdi chiia nguyen to K Vdy chon C Cac polime thuoc loai tcf nhan tao la A tot visco; ta nilon-6,6; tcf capron B tcf t a m ; tcf vinilon; tcf visco C ta nilon-6,6; ta capron; len D ta visco; ta xenluloza axetat; ta dong-arnoniac (Dai hoc 2012 - khoi B) Gidi Chii y rdng vai dang bdi tap nay, chi can phdt hicn mot loai ta niSi ddy da cho khong phdi Id to nhdn tao thi ta loai trii Vdy di ddng loai trii A, B, C vd chon D (ta nilon-6,6; tdni; len Id ta thien ta capron; ta vinilon Id ta tong hap, ta nhien) Vdy chon C Trong cac polime: ta thm, scfi bong, ta visco, ta nilon-6, ta nitron, nhOTng polime CO nguon go'c t\i xenluloza la D sgi bong va ta visco C sgi bong, ta visco va ta nilon-6 B ta visco va ta nilon-6 A ta t k m , sgi bong va ta n i t r o n (Dai hoc 2013 - khoi B) Gidi Tuang nitron; tu nhu can a tren, ta loai trii A, B, C vd chon D (ta tdm; ta ta nilon-6 khong c6 nguon goc til xenluloza) Vdy chon D Cho cac phat hiiu sau: (a) Trong bang tuan hoan cac nguyen to hoa hoc, crom thuoc chu k i 4, nhom VIB (b) Cac oxit cua crom deu la oxit baza (c) Trong cac hgp chat, so oxi hoa cao nhat cua crom la -H6 (d) Trong cac phan tfng hoa hoc, hgp chat crom(III) chi dong vai tro chat oxi hoa (e) K h i phan ufng vdi k h i CI2 dii, crom tao hgp chat crom(III) Trong cac phat bieu tren, nhijfng phat bieu dung la: A (a), (b) va (e) B (a), (c) va (e) C (b), (d) va (e) D (b), (c) va (e) (Dai hoc 2013 - khoi A) to Gidi De y rdng b) Id phdt bieu sai nen loai trie A, C, D (CrO Id oxit baza; CrOs la oxit axit; CrsOs Id oxit liiang tinh) Vay chon B Cho cac chat : caprolactam (1), isopropylbenzen (2), acrilonitrin (3), glyxin (4), v i n y l axetat (5) Cac chat c6 kha nang t h a m gia phan uTng trung hcfp tao polime la A (1), (2) va (3) B (1) (2) va (5) C (1), (3) va (5) D (3), (4) va (5) Gidi Vi caprolactam (1) cho dugc phan iXng triing hgp, nhitng isopropylbenzen (2) khong cho dugc phan iCng triing hgp nen loai trit D, A, B Vay chon C 10 Cho can bang hoa hoc sau: 2SO2 (k) + O2 (k) < > 2SO3 (k) ; AH < Cho cac bien phap : (1) tang nhiet do, (2) tang ap suat chung cua he phan ufng, (3) nhiet do, (4) diing them chat xuc tac V2O5, (5) giam nong SO3, (6) giam ap suat chung cua he phan ufng NhOfng bien phap nao lam can bang tren chuyen dich theo chieu thuan? A (2), (3), (4), (6) B (1), (2), (4) C (1), (2), (4), (5) D (2), (3), (5) Gidi Chu y rdng chat xuc tdc (4) khong Idm can bdng chuyen dich nen loai trie A, B, C Vgy chon D 11 Cho bon dung dich c6 cung nong mol sau day: (1) H N C H C O O H , (2) C H C O O H , (3) CH3CH2NH2 va (4) C2H3COOH Day xep theo thuf tiT p H tang dan la: A (3), (1), (2), (4) B (4), (1), (2), (3) C (2), (3), (1), (4) - D (4), (2), (1), (3) Gidi Khong it hoc sinh boi roi a cdu hoi ndy khong ndm dUgc luc axit cua axit chita no C2H3COOH Id mgnh hay yeu han so vai axit CH3COOH phiiang phap loai trie nhu Hay dung sau: Vi dung dich CH3CH2NH2 c6 moi truang baza nen pH cua dung dich ndy phdi Ian nhdt so dung dich Vgy loai trii A, C NhiCng dung dich NHoCH^COOH c6 pH xdp xi Id 7, dung dich CH3COOH phdi CO pH < nen loai trie tiep B Vgy chon D 12 Cho hSn hcfp X gom Fe203, ZnO va Cu tac dung \6i dung dich H C l (diT) thu di/cfc dung dich Y va phan khong tan Z Cho Y tac dung vc;i dung dich NaOH (loang, du) thu d'Jgc ket ttia: A Fe(0H)3 va Zn(0H)2 B Fe(0H)2 Cu(0H)2 v^ Zn(0H)2 C Fe(0H)3 D Fe(0H)2 Cu(0H)2 11 Do hon hop anken thu difcfc gom 0,5a mol C2H4 va 0,45b mol C3H6 nen ta c6 he: a + b = 0,6 |a = 0,36 " 28.0,5a+ 42.0,45b = 9,576 [ b = 0,24 60.0,24 Suyra %m,.^„^oii = 46.0,36 + 60.0,24 = 53,48% Vay chon D 15 Cho 10 gam r S n X gom M g va Fe vao coc diTng 210 m l dung dich Cu(N03)2 2M Khuay deu de phan ufng xay hoan toan dtfofc dung dich Y va 16 gam ran Z Cho dung dich NaOH du vao dung dich Y dugc ket tua T Phan t r a m khoi \\Jang M g X la A 30% B 50% C 70% D 9Q.% • Nhdn xet Neu chufng m i n h di/Oc a mol M g va b mol Fe hon hap X da phan iJng het thi 16 gam r a n Z chi la (a + b) mol Cu, tif de dang giai he t i m a, b va CO ket qua can t i m • Gidi Goi a, b la so mol M g va Fe X, ta c6 24a + 56b = Ta 24a + 24b < 24a + 56b CO O a + b < — = 0,41 24 « "c.so,dapha„.,„ = a + b 11,42 nen M g va Fe da phan ufng het la diing! Cac em phai hieu " d i n h l y " sau chi c6 mot chieu: Neu 10 gam hSn hap Mg vd Fe deu dd phan line het thi rdn Z phdi cd khoi luang Ian han 11,42 gam O day khong c6 chieu ngi/cfc l a i : Neu rdn Z c6 khoi luang Ian han 11,42 gam thi 10 gam hSn hap Mg vd Fe deu dd phan ling het 113 Chinh v i vay phai c6 dif kien ve so' mol CUSO4 de khang dinh M g va Fe deu da phan uTng he't 16 Cho 3,87 gam h6n hop X gom M g va A l vao 250 m l dung dich HCl 2M Dung dich sau phan ufng chufa D MgClz; AICI3 va H C l C chi chufa AICI3 B chi chuTa MgCla A MgCl2 va AICI3 • Nhdn xet Ta phai so sanh tong (2a + 3b) la so' mol H C l to'i thieu can dung de h6a tan he't hon hcfp gom a mol M g va b mol A l vcri 0,5 mol H C l de cho • Giai Gpi a, b la so mol M g va Fe X, ta c6 24a + 27b = 3,87 Ta C O 24a + 24b < 24a + 27b C> 8(3a + 3b) « p X gom mot oxit k i m loai kiem v^ mot oxit k i m loai kiem tho lu'ong dtf dung dich H C l , sau c6 can dtfac h6n hop mudi Y Dien phan nong chay hoan toan Y dugc 2,3 gam hon hap k i m loai Z a catot va 2,016 l i t (dkc) k h i T d anot Neu luyen them 0,8 gam Ca vao h5n hap Z di/cfc hgp k i m W Ca chie'm 37,5% ve so mol Phan t r a m khdi liigng oxit k i m loai kiem X la A 51,72% • Nhdn B 83,33% C 28,57% D 40,10% xet Sa bai toan: X A j O : a mol BO: HCl binol >Y A C l : 2a mol Z : 2a mol A va b mol B dpnc T : (a + b) mol Cl^ B C L : b mol Bai toan nhat t h i e t phai t i m gia t r i a, b A, B Viec chan tren %Ca (theo so mol) W neu Z khong c6 Ca se giup khang dinh Z c6 Ca • Giai Gia sijf X gom a mol A2O va b mol BO t h i hon hgp muoi gom 2a mol ACl va b mol BCI2 Nhtf vay h6n hgp k i m loai Y gom A : 2a mol B : b mol 114 Tacon^, = a + b = — — = 0.09 22 A Gia sijf Z k h o n g chijfa Ca t h i k h i t h e m 0,8 g a m C a tufc 0,02 m o l C a v a o Z t a difcfc h6n h o p W t r o n g do: 0,02 %Ca., ,hco«tmoim,ngw 2a + b + 0,02 M g C l g + 2FeCl2 N h i f n g k h i cho M g dU vao d u n g d i c h FeCl3 se t h u di/oc Fe k i m l o a i : M g (dxi) + 2FeCl3 > M g C l + 2Fe 117 b/ K h i cho Fe dtf vao dung dich AgNOs dU t h i thu Auac Fe^^: Fe (da) + 2AgN03 > Fe(N03)2 + 2Ag NhiTng k h i cho Fe vko dung dich AgNOa dii se thu di/cfc Fe^*: F e + SAgNOg idii) > Fe(N03)3 + 3Ag V i d u 4: Co bao nhieu phan uTng du'dri day tao dcrn chat? 1/ FeCl3 + H2S 3/ I2 + H2S > 2/ Fe2(S04)3 + K I > 4/ A l + Fe(N03)3 (di/) — ^ > 5/ SnCl2 + FeCla A - > B C D Gidi Cac phan uTng xay ra: 1/ 2FeCl3 + H2S > 2FeCl2 + S + 2HC1 2/ Fe2(S04)3 + K I 3/ I2 + H2S > 2FeS04 + I2 + H2SO4 > I I I -f S 4/ A l + 3Fe(N03)3 (du') > A1(N03)3 -i-3Fe(N03)2 5/ SnCIa + 2FeCl3 > SnCU + 2FeCl2 Vay CO phan ufng tao dcrn chat Vay chon A V i d u 5: Nho tCr tii dung dich X vao ong nghiem chufa nifdc brom thay mau nau ciia niTdtc brom sam dan Dung dich X la D dung dich NaOH C dung dich H I B dung dich HoS A dung dich H C l Gidi K l i i nho tii tii dung dich H I vao ong nghiem chuTa nude brom, ta thay nvldc brom s l m mau dan c6 siJ tao I2 c6 mau t i m than phan ufng: Br2 + 2HI > 2HBr + I2 Vay chon C V i d u 6: V i Fe the hien so' oxi hoa -1-3 phan ufng vdi cac halogen F2; CI2 va Br2, nhiing l a i the hien so' oxi hoa +2 phan ufng v6i I2? Gidi Can cuf vao thuf tii day dien hoa: 118 Bi- CL Fe •" • 21 F e ' " ' ' ' B r ' C r F thi phan ufng cua Fe vdi cac halogen trtfdc het deu tao Fe^*, nhiftig sau F2; CI2 va Br2 deu c6 kha nang oxi hoa tiep Fe^'' Fe^", k h i l o khong c6 kha nang V i the' Fe the hien so oxi hoa +3 phan ufng vdri cdc halogen F2; CI2 va Br2, nhiMg lai the hien so oxi hoa +2 phan ufng vdi I2 Cac phUcfng t r i n h phan ufng xay ra: 2Fe + 3F2 2Fe 2Fe > 2FeF3 + 3CI2 -> 2FeCl3 + 3Br2 -> 2FeBr3 Fe + I2 ^ Fel2 BAI TAP AP D U N G Co phan ufng sau: 2FeBr2 + Bra 2NaBr + CI2 (1) 2FeBr3 — (2) -> 2NaCl + Bra Phat bieu diing la A Br2 CO t i n h oxi hoa manh han CI2 B Cr CO t i n h khuf manh hcfn B r ' C Fe'" CO t i n h khijf yeu hcfn CV D Fe^" CO t i n h oxi hoa yeu hcfn CI2 (Dai hoc khoi B/2008) • Nhdn xet Day la mot bai tap l i thuyet de tuyen sinh nen t h i sinh t a t nhien khong the c6 tay day dien hoa Do cau hoi c6 lien quan den t i n h khuf va tinh oxi hoa cua cac chat hoac cac ion, tufc c6 lien quan den cac cap oxi hoa khuf nen hudng giai quyet la diing qui tSc a • De Gidi phan iJng (1) xay ra, thuf tii cac cap oxi hoa- khuf day dien hoa phai la: De Fe Fe'" Br, 2Br' phan ufng (2) xay ra, thuf tif cac cap oxi hoa- khuf day dien hoa phai la: Br CL 2Br 2CL 119 V a y thiif t i i cac cap o x i h o a khuf t r o n g day d i e n hoa l a : 2Br" Fe'" Br^ Fe'^ CI, 2Cr C h i i y r a n g t r o n g day d i e n hoa, tuf so l a cac c h a t o x i hoa, v d i t i n h oxi hoa t a n g d a n tiT t r a i s a n g p h a i ; mSu so' l a cac c h a t khuf, vori t i n h khijf g i a m d a n tU t r a i sang p h a i Vay chon D Co bao n h i e u p h a n ufng diTdri day k h o n g xay r a : + 2/ M g ( d i f ) + 1/ Z n ( d i r ) 3/ H2S + I2 2CrCl3 2CrCl3 S > 3CI2 5/ 2FeBr3 + CI2 4/ C r C l + • Nhdn > + SMgClg ^> SZnCh > + + 2Cr 2Cr 2HI 2CrCl3 2FeCl3 + > 3Br2 xet De d a n g diTa vao day d i e n hoa v a q u i tac a de n h a n r a (1) l a p h a n ufng khong diing • Giai P h a n ufng (1) p h a i v i e t l a : Zn(dLr) + 2CrCl3 > ZnClg + 2CrCl2 Cho cac p h a n ufng sau: + Fe'" + Sn'^ 2Fe'" > Ag" Sn'" > + Fe'" 2Fe^^ + Ag D a y sap xep t h e o thuf t i i t a n g d d n t i n h o x i h o a c^c i o n k i m l o a i l a : A A g " , S n ' \" B S n ' ^ F e ' ^ C Sn^", A g " , F e ' " • Nhdn Ag" D A g " , F e ' " , Sn'" xet H o a n t o a n t u o n g t i f n h i i t r e n , t a d i i n g qui tac a de g i a i quyet va'n de da neu • De Giai p h a n ufng (1) x a y r a , thuf i\i cac cap o x i hoa- khuf t r o n g day d i e n hoa phai la: De F ,2+ e' Sn'" Fe'" Sn'- p h a n ufng (2) x a y r a , thuf t i i cac cap o x i hoa- khuf t r o n g day d i e n hoa Fe-" phai la: Ag_ Fe'" • • • Ag 120 Vay thijf tiT cac cap o x i h o a khijf t r o n g day d i e n h o a l a : Sn^ Fe^ Ag^ • • • S n ' * • • • Fe^* • • • A g • • • Do t i n h o x i hoa cua Sn^"^ < Fe^* < A g * V a y c h o n B Co bao n h i e u p h a n ufng difdri day tao muo'i Fe ( I I I ) ? 1/ Hoa t a n Fe304 t r o n g d u n g d i c h H I 2/ Dot day Fe t r o n g h o i i o t 3/ Hoa t a n F e ( N ) t r o n g H S O l o a n g 4/ Cho d u n g d i c h FeCla vao d u n g d i c h AgNOa (dii) 5/ Hoa t a n Fe (dtf) t r o n g H N O l o a n g B A Nhdn C D xet Cac chat d u n g du t r o n g p h a n ijfng p h a i h i e u l a k h i p h a n ijfng da x a y r a x o n g , chiing vSn dif P h a n ufng (4) p h a i cho AgNOa d i i , tufc A g * d i f de t r a n h trtfcfng hcrp Ag* d u n g t h i e u n e n se b i k e t t u a h e t t r o n g A g C l , k h i se k h o n g A g * de oxi hoa Fe^* t h a n h Fe^* • Gidi Cac p h a n ufng xay r a : 1/ Fe304 + S H I 2/ Fe + I2 3Fel2 + I2 + 4H2O > > Fela 3/ 3Fe2* + H * + N O , 4/ Fe^* + Ag* 5/ 3Fe + 8HNO3 > > 8Fe^* + N O + Fe'* + 2H2O Ag > 3Fe(N03)2 + N O + 4H2O Vay chon A Co m o t m a u bac b i I a n t a p c h a t l a n h o m v a k e m De n g h i phiJcfng p h a p hoa hoc d a n g i a n de t i n h che m a u bac t r e n • Nhdn xet Ta can l o a i bo cac t a p c h a t l a A l v a Z n r a k h o i mSu A g t r e n n e n each l a m l a ngam m a u A g da cho t r o n g m o t lifcfng d i i cac d u n g d i c h c6 k h a n a n g h o a t a n A l va Zn (tufc o x i h o a diigc A l v a Z n t h a n h A l ' * v a Zn^*) T a t n h i e n d u n g d i c h n a y phai k h o n g h o a t a n diiac A g (tufc k h o n g o x i h o a diigc A g t h a n h Ag*) • Gidi + Cdch 1: N g a m m ^ u bac t r e n vao lufcrng d i i d u n g d i c h N a O H , t o a n bo A l v a Zn se t a n h e t , l a i l a A g + Cdch 2: N g a m m a u bac t r e n vao lufong d i i d u n g d i c h H C l (hoac H S O loang), t o a n bo A l v a Z n se t a n h e t , l a i l a A g 121 + Cdch 3: N g a m m t u bac t r e n vao l u g n g d i i d u n g d i c h AgNOa, t o a n bo A l va Z n se b i Ag^ o x i hoa h e t t h a n h Al^^ va Zn^\n l a i l a A g + Cdch 4: N g a m mSu bac t r e n vao lUcfng dtf d u n g d i c h Fe^*, t o a n bo A l va Z n se b i Fe^^ o x i h o a h e t t h a n h A l ^ * va Z n ^ \n l a i l a Ag N h u n g m o t l a k i m l o a i M vao d u n g d i c h Fe(N03)3 Sau m o t t h d i g i a n lay la M r a can thaiy k h o i iticmg k h o n g doi K i m l o a i M l a A Fe • Nhdn B Cu C M g D Pb xet D a n g t o a n " n h i i n g " l a d a n g t o a n m a t a l u o n x e m t o a n bo k i m l o a i s i n h b a m h e t vao l a k i m l o a i da n h u n g vao (5 day k h o i li/ang l a k i m l o a i M k h o n g doi sau k h i n h u n g n e n hoac phdn bugc phdi c6 kim mat di phdn • loai sinh bdm ling khong xdy ra, hoac ve mat vao Id M de "qudn binh" khoi dinh tink, lUgng M dd I'ing Gidi De y thuf tiJ cac cap o x i hoa- khijf t r o n g day d i e n hoa l a : Mg^" Mg Fe^ " TCf t h a y r S n g • Fe Ph^ • • • Pb Cu^ ' ' • Cu ' •' Fe^ Fe'" ca k i m l o a i da cho deu t a n r a k h i n h i i n g vao d u n g dich F c ' " , n h i f n g sau c h i c6 M g c6 k h a n a n g p h a n l i n g t i e p tuc vdri m u o i F e ' " vifa tao t h a n h de tao r a sSt k i m l o a i b a m t r e n be m a t la M g , n h d k h o i liicfng k h o n g g i a m d i n h i i l a k i m l o a i l a i V a y M l a M g V a y c h o n C N h i i n g m o t l a k i m l o a i M vao d u n g d i c h Fe(N03)3 Sau m o t thori g i a n l a y la M r a can t h a y k h o i Itfang k h o n g doi Co bao n h i e u k i m l o a i t r o n g so' cac k i m l o a i sau t h o a m a n t i n h c h a t ciia k i m l o a i M : A g ; A l ; Z n ; M g ; Fe v a Cu? A • Nhdn B C D xet Ti/cfng t i i n h i / t r e n , de k h o i Itfong l a k i m l o a i M k h o n g d o i sau k h i n h i i n g t h i hoac phdn xdy ra, hoac ve mat dinh ling khong tinh, bugc phdi c6 kim loai sinh vao Id Wl T u y vay, d i n h t i n h t h i i c s\i v a n chifa d u , v i de k h o i lifc/ng la bdm M k h o n g d o i t h i k h o i ItfOng k i m loai M t a n r a p h a i b S n g vdfi k h o i lifcfng k i m l o a i s i n h r a da b a m vao l a M « Gidi Thuf t\i cac cap o x i hoa- khuf t r o n g day d i e n hoa l a : Mg'" Mg Al'' ' " Al Fe2 Zn^ ' " Zn • " ' Fe PlT^ ' ' ' Pb Cu^ " ' Cu Fe^ ' ' ' Fe'" Ag^ A\ V i k h o n g xay r a p h a n ufng giufa A g v a d u n g d i c h Fe^" n e n A g l a m o t lifa chon diing 122 -If Ngoai r a M c6 t h e l a Z n ; A l hoac M g c h u n g t^c d u n g t i e p di:foc vdi Fe^* vCfa s i n h r a , tao t h a n h m o t li/crng Fe b a m vao cdc 1^ k i m l o a i + Neu M l a Z n TrLfdc h e t x a y r a p h a n ufng: Zn+ 2Fe=^^ > Zn^^ + (1) (1) l a m k h o i itfcfng l a Z n p h a i g i a m T u y n h i e n neu n h u n g du l a u se xay r a tiep p h a n ufng: Zn+ Fe'" > Zn'" + Fe (2) (2) t i e p tuc l a m kho'i lifcrng l a Z n g i a m , v i neu c6 65 g a m Z n t a n r a t h i c h i c6 56 gam Fe b a m vao Vay loai Z n + Neu M l a A l Trirdc h e t xay r a p h a n ufng: Al-h 3Fe'^" > Al'" + 3Fe'" (1) (1) l a m k h d i lu'cfng l a A l p h a i g i a m T u y n h i e n n e u n h i i n g d u l a u se xay r a tiep p h a n ufng: 2A1 + 3Fe'" > A ' " + 3Fe (2) (2) se l a m k h d i lifcfng l a A l t a n g , v i n d u c6 54 g a m A l t a n r a t h i c6 d e n 168 gam Fe b a m vao, h o a n t o a n c6 k h a n a n g " q u a n b i n h " v d i t o n g k h d i lilcyng A l da tan «3r (1) v a (2) Vay A l t h o a dOf k i e n ciia k i m l o a i M f Neu M l a M g Trifdrc h e t xay r a p h a n ufng: Mg+ 2Fe'" > Mg'" H- 2Fe'" (1) (1) l a m k h d i lifgng l a M g p h a i g i a m T u y n h i e n neu n h i i n g d i i l a u se xay r a tiep phan l i n g : Mg+ Fe'" > Mg'" + Fe (2) (2) se l a m kho'i Itfong l a M g t a n g , v i neu c6 24 g a m M g t a n r a t h i c6 d e n 56 gam Fe b a m vao, cQng h o a n t o a n c6 k h a n a n g " q u a n b i n h " v d i t o n g k h d i li/crng Mg da t a n r a cf (1) va (2) Vay M g t h o a di7 k i e n ciia k i m l o a i M Tom l a i c6 k i m l o a i t h o a de b a i l a : A g ; A l va M g V a y c h o n B N h i i n g m o t l a k i m l o a i M , hoa t r i I I , c6 khd^i liicfng 9,6 g a m vao d u n g d i c h X chila d o n g t h d i 0,1 m o l FeS04 v a 0,12 m o l Fe2(S04)3 Sau m o t t h d i g i a n l a y la M r a , duWc d u n g d i c h Y c6 khd^i l i W n g b k n g vdri khd^i liicfng d u n g d i c h X La k i m l o a i M l a y r a d e m hoa t a n h e t t r o n g d u n g d i c h H C l du' dtrdc 6,272 l i t H2 (dkc) S d m o l FeS04 c6 t r o n g d u n g d i c h Y l a A 0,24 m o l B 0,3 m o l C 0,25 m o l D 0,4 m o l 123 • Nhdn xet Day l a mot bai toan dinh lifcfng minh hoa cho v i du cr t r e n Chii y khoi liicfng dung dich muoi trtrdrc va sau k h i nhung khong doi, dong nghIa vdri khoi liiomg la k i m loai M trtrdtc va sau k h i nhung cung khong doi • Gidi Do Fe^^ de b i khuf t h a n h Fe^^ so vdi Fe^^ h i khijf t h a n h Fe Do tnldrc het xay phan ufng: M + Fe2(S04)3 ^ MSO4 + 0,12 mol 0,12 mol 2FeS04 0,24 mol Nhi/ng neu chi xay r a phan ufng t h i khoi li/cfng dung dich Y phai Idfn han khoi lucfng dung dich X Theo de t h i kho'i lifcfng dung dich X va Y bang chufng to phai xay tie'p phan ufng: M + a mol FeS04 > MSO4 a mol + Fe a mol 0,12 - a) m o l k i m loai M Nhif vay la M luc lay can gom: ( ^FeM : a mol bam vao Vi M va Fe deu tac dung vdi HCl giai phong H2 theo t i le mol : nen ta c6: Q ^ A '7 {—-0,12-a) +a= ^ = 0,28 M 22,4 «M=.24(Mg) M a t khac kho'i liJgng dung dich X bang kho'i Itfcrng dung dich Y nen khoi lifgng la M g khong doi luc lay can Vay ta phai c6 m^g tan = 24(a + 0,12) = 56a « bam vao a = 0,09 (mol) Do so mol FeS04 dung dich Y = (0,24 + 0,1) - a = 0,25 mol Vay chon C Mot cac ufng dung ciia day dien hoa la dung de t i n h suat dien dong chuan cua itl6t pin dien hoa bat k i T l n h suat dien dong chuan cua cac pin dien hoa Zn - Cu; A I - Zn; M g - Ag; Zn - H^; H2 - Ag • Luu y Pin dien hoa la mot t h i e t b i gom hai co'c thijy t i n h : mot co'c c6 kim loai A nhiing vao dung dich A ' " , mot co'c c6 k i m loai B nhung vao dung dich B"'\t ong t h u y t i n h h i n h chiJ U chufa dung dich KNO3 hoac NH4NO3 (goi la cau muoi) noi giQa hai coc Hieu dien the' l Fe'" + Ag 0,02 mol 0,02 mol Vay mAg = 108.0,12 = 12,96 gam Vay chon C » Liiu y Khi giai toan ve Fe tac dung v6i dung dich Ag" , de dii doan san pham sinh n ra, ta tinh t i le k = Neu: n + — ^ < : R i n sau phan ijtng gom Fe dii va Ag, vdi n^^ = n^^ + n +2 < > : Kan sau phan ufng chi la Ag, vdi n^^ = 3n^^^ '^^ ^ : RSn sau phan ufng chi la Ag, vdi n , = n , 13 Cho 5,6 gam bot sat vao 160 m l dung dich AgNOa M Sau k h i cac phan ufng xay xong t h i kho'i liiong bac thu difoc la bao nhieu gam? A 32,40 B 16,20 C 12,96 D 21,60 « Giai Ta CO n F e - 0,1 mol; n^^^„^ =0,32 mol n ^ Vi > nen n^^^ = 3n,,^.- 0,3 mol Vay mAg = 108.0,3 = 32,4 gam Vay chon A 14 Cho 5,6 gam bot sat vao 90 m l dung dich AgNOa M Sau k h i cdc phan ling xay xong thu diictc ran X cd kho'i Itfcfng la A 20,00 B 19,44 C 32,40 D 21,60 • Giai Ta cd npe - 0,1 mol; n =0,18 mol n Vi < nen Fe dtf sau phan ufng Ran X gom 0,18 mol Ag va (0,1 - 0,09) = 0,01 mol Fe d\i Vay m x - 108.0,18 t- 56.0,01 = 20 gam Vay chon A 127 ... 13 7c + 15 3d = 21, 9 T h e o de t a c6 he: < c + d = 20,52 17 1 = 0 ,12 a 1, 12 = 0,05 - +c = 22,4 36 23(a + 2c) + l(c + d) + 62(b + d) = 21, 9 a + 2c = 0 ,1 23(a + 2b) + 13 7(c + d) + 16 (b + d) = 21, 9... 2 ,10 mol < 2 ,16 mol 19 44 - Loai trie B, vi neu chon m = 19 ,44 thi UAI =— = 0,72 mol.Khi dd 2 .1 n-eiectron doAi cho = 0,72.3 = 2 ,16 chitng to khdng tgo NH4NO3 Do dd rn.,nu6i = rn + 62 (10 .0 ,12 ... = 2 ,16 mol, do: 17 28 - Loai tril A, vi neu chon m = 17 ,28 thi nAi -—'— = 0,64 mol Khi dd 27 rieiectron Ai cho = 0,64.3 = 1, 92 mol < 2 ,16 mol 18 90 — • Loai trii C, vi neu chon m = 18 ,90 thi