bồi dưỡng học sinh giỏi hóa học 9 cao cự giác

540.76 PGS.TS CAOCL/GlAC B452D Tai lieu danh cho: Hoc sinh gioi va chuyen hoa hoc • Sinh vien sa pham hoa hoc Giao vien day boi dUSng hoc sinh gioi hoa hoc V 11 NHA XUAT BAN DAI HOC QUOC GIA HANOI B6I Dciam HQC svfH (abi Tai lieu danh cho: Hoc sinh gioi va chuyen hoa hpc Sinh vien sU pham hoa hpc Giao vien day boi di/6ng hpc sinh gioi hoa hpc 30!! i - THi/ NHA jim BhlH JHvk^ JAT BAN DAI HOC QUOC GIA HA NQI Jji not dAu T r o n g q u a t r i n h d a y h o c cV T H C S da c n h i e u e m h o c s i n h h o c 16 n a n g k h i e u ve k h a n a n g t i i d u y va h o c t a p m o n hcSa hoc C h a n g h a n , ccS e m t h i c h k h a m p h a t h e gicvi t u n h i e n n h u t i m h i e u c a u t a o cac chat t h i f c f n g g a p t r o n g c u o c s o n g va d u d o a n , g i a i t h i c h cac t i n h c h a t cua c h u n g C u n g c o e m thi'ch l a m cac t h i n g h i e m n h o de t u n h i e u va chiVng m i n h cac h i e n tUOng r o i n i t q u y l u a t N h i e u e m c t r i nhci dac biet ve sU p h a n loai cac chat va t i n h chat ciia c h i i n g , t h e h i e n sU sang t a o va t h o n g m i n h t r o n g each g i a i b a i t a p , T u y n h i e n , cac e m m u o n p h a t t r i e n dUOc k h a n a n g t U d u y ciia m i n h v e m o n h o a h o c t h i c a n p h a i duOc t r a n g b i m o t each c he t h o n g t i f l y t h u y e t d e n k l n a n g g i a i b a i t a p va cac ufng d u n g thUc h a n h p h u h o p v i sU p h a t t r i e n n h a n thufc ciia lila t u o i h a o h i i n g va p h a n khcVi D e g i i i p giao v i e n , p h u h u y n h va h o c s i n h bac t r u n g h o c cO -id ccS t h e m t U l i e u b o i dUc^ng h o c s i n h g i o i m o n h o a h o c , c h i i n g t o i b i e n soan b o sach " B o i ditofng h o c s i n h g i o i H o a h o c " t h e o cac n o i d u n g sau: A L i t h u y e t t r o n g tarn B PhUcfng p h a p g i a i b a i t a p C B a i t a p ap d u n g D HUcVng d a n g i a i E Bai t a p t U l u y e n ( t i i l u a n va t r i e n g h i e m ) H y v o n g vofi k e t cau va n o i d u n g ciia b o sach, p h a n n a o se l a m c h o d o c gia, dac b i e t la cac e m h o c s i n h t i m t h a y nhufng d i e u b i c h va n i e m say m e t r o n g viec h o c tap h o a h o c T r a n cam d n ! C a c tac gia Nhd sach KJtajtg Vietxitt trdn tronggim thieu toi Quy doc gid vd xin lang nghe moi y kim doug gop, de aion sach ngdy cdng hay horn, bo ich han Thu xin giti ve: Cty T N H H Mot Thanh Vien - Dich V u Van Hoa Khang Viet 71, D i n h T i e n H o a n g , P D a k a o , Q u a n 1, T P H C M T e l : (08) 39115694 - 39111969 - 39111968 - 39105797 - F a x : (08) 39110880 Hoac Emaih khangvietbookstore@yahoo.com.vn T::Ty^L\ini-i mi v uvvn Chuxrnq 1: M O T S OP H U O N G PHAP js^nang vtet GIAI BAI TAP H O A H O C PhiTdng phap tinh theo cdng thuTc hoa hoc • Ooi vdi hdp chat c6 hai nguyen to: TacoCTTQ: A,By '"^^ o/„m^ = — ^ 0 % y.M„ %m„=^-^.100% M ^ % m , ^ xJVI, % m „ y.M„ B y B m , ^ xjyi^ ' m„ y.M„ B yB • Doi vcfl hdp chat c6 nhieu nguyen to: Ta CO (TTTQ: AxByCz + each 1: Thiet lap cong thiTc ddn gian nhat ((TTOGN) x:y:z=^:^:^^CTDGN M, M M , Hay: x:y:z = A% M, Di/a vao Mhdp chat : B% C% : M3 M , CTPT (TTOGN + each 2: Thiet lap cong thuTc phan tCf (CTPT) M,.x M^.y mg M,.Z_MA,B,C, ^ ^ ^ ^ ^ ' ^\B^C^ Hay: ^ ^ ^ J } o ± ^ A% B% 0% 'V^^ 100 cTPT ' Vi du 1: Mot hdp chat cua kim loai R vdi oxi (kim loai R chu'a biet hoa tri) Trong oxi chiem % ve khoi lu'cJng Xac dinh ten kim loai R? Hu'dng dan: Ooi vcfi dang chijng ta can xay di/ng phu'dng phap giai cho hoc sinh theo cac bu'dc sau: + Oat cong thut tong quat (CTTQ) va suy hoa tri cua R j,;,^ ^\ CFTQ: R „ ^ Hoa tri ciia R : ^^Z + Ap dung cong thCrc:°!^I!1KL= va hoa tri cua R ^ (jg' thiet lap bieu thtfc hien he giiJa MR Bdi dudng hgc sink gidi Hda hgc — Cao Cxi Gidc M„ = Ll^ hoa tri cue R la " 3.x ^ 70.y_ 30.x 16 Ta c6: " /x nen 56 2y x + Cuoi cung ta bien luan hoa trj de xac djnh ten kim loai R (Li/u y: kim loai c6 hoa tri tif den 4, phi kim hoa tri tif den 7) MR 18,7 37,3 Loai 56 74,7 (Fe) Loai Loai Ket luan: Kim loai c6 hoa tri I I I va M = 56 la Fe Vi dM 2: Mot oxit c6 chu^a % oxi ve khoi lydng Xac djnh cong thCrc Oxit tren Hitaing dan: + Dat cong thiTc tong quat (CTTQ) va suy hoa trj cua nguyen to iai CTTQ: R^Oy ^ Hoa tri cua R : + Ap dung cong thCrc: %m3.x =— MB de thiet lap bieu thirc hien he giiJa M R y K va hoa tri cua R Ta c6: 4?^ =^ 60.x 16 »/ " 16 2y x M = ^ 3.x nen hoa tri cua R la de xac djnh ten nguyen to R Cuoi cung ta bien luan hoa trj 2y/ / x MR 5,3 10,6 16 21,3 26,7 32 37,3 Vay nguyen to R la lull huynh => CTPT Oxit: SO3 V I du 3: Mot hcJp chat gom Kim loai chu-a biet hoa trj vdi luU huynh (biet S c6 hoa tri II), lu'u huynh chiem 36,36% ve khoi luWng Xac dinh cong thirc phan tCr hdp chat tren? Hu-dngdan: ' ^ CTTQ: R^Sy ^ Hoa trj cua R : ^v/ | %mg.X M va hoa trj cua R 63.64.y^M, 36,36.x 56 2y => M , = • X 32 2y/ / X MR '\ 28 56 84 112 Vay nguyen to R la Fe Phu'G^ng p h a p bao toan khoi lu'dng - Nguyen tac cua phUdng phap Tong khoi lu-dng cac chat tham gia phar ling bang tong khoi luWng cac chat tao sau phan uTng - Trong mot phan trtig hoa hoc c6 n chat (ke ca chat tham gia va chat tac thanh), neu biet khoi lu'dng cua (n - 1) chat thi van dung djnh luat bao toar khoi lu'dng Vi du 1: Cho luong khf CO di qua m gam Fe304 sau phan u'ng thu du'dc 24,y gam chat ran, va 17,6 gam CO2 Tim m? Hitdng dan: Phan tich dC kien de bai, nhan thay khong the tinh t r u t tief vi so chat tham gia va chat tao la bon nhuYig chi biet khoi lu'dng chat Mat khac chu'a biet khoi lu'dng Fe304 da tham gia phan u'ng het hay cor du" nen khong tinh theo kieu bai toan can bang mol binh thu'dng Do ta di/a vao phu'dng trinh phan Crng de tim them du' kien cho bai toan Fe304 + CO — FeO+ CO ^ 3Fe0 + CO2 -> Fe + CO2 Qua phu'dng trinh nhan thay: 17,6 = 0,4mol 44 Khi du du' kien ta ap dung dung djnh luat bao toan khoi lu'dng: "2 f^Fe^o =31,1gam V i d u 2: Cho luong khf CO du' di qua hon hdp X gom cac oxit: Fe304, AI2O3, MgO, ZnO, CuO nung nong, sau mot thdi gian thu du'dc ho hdp khf Y ve 23,6 gam chat ran Z Cho Y Ipi qua binh difng dung djch nu'dc voi du", thay CO 40 gam ket tua xuat hien Xac dinh khoi lu'dng X Hitdng dan: n CaCOg 40 | QQ = 0,4mol COz + Ca(0H)2 ^ CaCOj i + H2O (1) 0,4