7/29/2019 10 Olympic XII DN 2006 de Thi

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K THI OLYMPIC 30 THNG 4 LN TH XIITI THNH PH NNG - KHA NGY 17 THNG 4 NM 2006

MN HA HC LP 10Thi gian: 180 pht (khng k thi gian giao )

CHNH THC( ny gm c 2 trang)

Cu I (4 im)1. Trong cc cu trc c th c sau y, nhng cu trc no tn ti u tin hn? V sao?

Ion ICl4-: Phn t TeCl4

IClCl Cl

ClI

ClClCl

Cl

(a) (b) (c) (d)

TeCl

ClCl

Cl

TeClCl

Cl

Cl

2. Ti sao nc nh hn nc lng? (c v hnh minh ha)3.

137Ce tham gia phn ng trong l phn ng ht nhn, c chu k bn hy 30,2 nm. 137Ce l mttrong nhng ng v b pht tn mnh nhiu vng ca chu u sau mt v tai nn ht nhn.

Sau bao lu lng cht c ny cn 1% k t lc tai nn xy ra.4. Da theo thuyt MO, hy gii thch t tnh ca phn t F2 v ion CO+.

Cu II (4 im)1. Cho cc d kin:

N2O4 (k) 2NO2 (k)

)mol/kJ(Hoht9,665 33,849

)mol/kJ(So298304,3 240,4

Gi thit rng bin thin entanpi v entropi phn ng khng thay i theo nhit . Phn ng st xy ra theo chiu no ti nhit : (a) 0oC v (b) 100oC.

2. Cho hn hp kh A gm H2 v CO c cng s mol. Ngi ta mun iu ch H2 i t hn hp Abng cch chuyn ha CO theo phn ng:

CO (k) + H2O (k) CO2 (k) + H2 (k)Hng s cn bng KC ca phn ng nhit th nghim khng i (toC) bng 5. T l s molban u ca CO v H2O bng 1 : n. Gi a l % s mol CO b chuyn ha thnh CO2.(a) Hy thit lp biu thc quan h gia n, a v KC.(b) Cho n = 3, tnh % th tch CO trong hp cht kh cui cng (tc trng thi cn bng).

Cu III (4 im)1. Dung dch A gm c H2SO4 0,05 M; HCl 0,18 M v CH3COOH 0,02 M. Thm NaOH vo dung

dch A n nng ca NaOH bng 0,23 M th dng, ta thu c dung dch A1.(a) Tnh nng cc cht trong dung dch A1.

(b) Tnh pH ca dung dch A1.(c) Tnh in ly ca CH3COOH trong dung dch A1.

Cho: Ka( 4HSO ) = 10-2; Ka(CH3COOH) = 10-4,75

2. Trn dung dch X cha BaCl2 0,01M v SrCl2 0,1M vi dung dch K2Cr2O7 1M, c cc qu trnhsau y xy ra: Cr2O72+ H2O 2CrO42+ 2H+ aK = 2,3.10-15

Ba2+ + CrO42 BaCrO4 93,911 10T =

Sr2+ + CrO42 SrCrO4 65,412 10T =

Tnh khong pH c th kt ta hon ton Ba2+ di dng BaCrO4 m khng kt ta SrCrO4.Cu IV (4 im)

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7/29/2019 10 Olympic XII DN 2006 de Thi

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1. Ngi ta lp mt pin gm hai na pin sau: Zn/Zn(NO3)2 0,1M v Ag/AgNO3 0,1M c th kh

chun tng ng l V76,0Eo

Zn/Zn2=+ v V80,0E

oAg/Ag

+=+ .

(a) Thit lp s pin.(b) Vit phng trnh phn ng khi pin lm vic.(c) Tnh sut in ng ca pin.(d) Tnh nng cc ion trong dung dch khi pin ngng hot ng.

2. Hon thnh phn ng oxy ha kh sau theo phng php thng bng electron:(a) FexOy + HNO3NnOm + ...(b) Cr 3+ + ClO3- + OH- ...

3. Hon thnh phn ng oxy ha kh sau theo phng php ion - electron:(a) SO32- + MnO4- + H2O ...(b) FexOy + H+ + SO42-Fe3+ + SO2 + S + H2O (vi t l mol SO2 v S l 1:1)

Cu V (4 im)1. Thc t khong pirit c th coi l hn hp ca FeS2 v FeS. Khi x l mt mu khong pirit bng

brom trong dung dch KOH d ngi ta thu c kt ta nu A v dung dch B. Nung kt ta

A n khi lng khng i thu c 0,2g cht rn. Thm lng d dung dch BaCl2 vo dungdch B th thu c 1,1087g kt ta trng khng tan trong axit.(a) Vit cc phng trnh phn ng.(b) Xc nh cng thc tng ca pirit.

2. Cho dung dch A cha 356 gam hn hp X gm NaBr v NaI tc dng vi 0,4 mol Cl 2. C cndung dch sau phn ng, thu c cht rn A c khi lng 282,8 gam.(a) Chng t rng ch c NaI phn ng.(b) Cho dung dch A trn tc dng vi Cl2. dung dch thu c cha hai mui th lng Cl2

ti thiu phi dng l 35,5 gam. Tnh s mol mi cht trong hn hp X.

Hc sinh c s dng bng h thng tun hon cc nguyn t ha hc v my tnh c nhntheo quy nh ca B Gio dc v o to. Gim th khng gii thch g thm.

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