CHUYN 1 :

CHUYN : I CNG HA HU C

CHUYN 1 : I CNG HA HC HU C

Bui 1: BI TP I CNG HA HC HU CI/Kin thc cn nh:- Tnh khi lng cc nguyn t:mC = 12= 12

mH = 2= 2

- Tnh thnh phn % khi lng cc nguyn t:%C =

%H =

nh lng N:mN = 28

%N =

nh lng O:mO = a (mC + mH + mN)%O = 100% - (%C + %H + %N)

* Ghi ch:

- Nu cht kh o kc (00C v 1atm):

- Nu cht kh o iu kin khng chun:

P: p sut (atm)V: Th tch (lt)R ( 0,082

Xc nh khi lng mol:

- Da trn t khi hi: ( (MA = MB.dA/B

Nu B l khng kh th MB = 29 ( M = 29.dA/KK

- Da trn khi lng ring a(g/ml): Gi V0 (lt) l th tch mol ca cht kh c khi lng ring a(g/ml) trong cng iu kin th M = a.V0

- Da trn s bay hi: Lm ha hi m(g) hp cht hu c th th tch n chim V lt. T tnh khi lng ca mt th tch mol (cng k) th chnh l M.Ha hi Cng iu kin VA = VB nA = nB

Xc nh % khi lng mi nguyn t trong HCHC:

Da vo khi lng hay (%) cc nguyn t. (x, y, z, t nguyn dng)

hoc = ( : ( : ( : (Lp CTPT hp cht hu c:1. Da vo phn trm khi lng cc nguyn t:

Hoc

2. Thng qua CTGN: T CTGN: C(H(O(N() suy ra CTPT: (C(H(O(N()n.

M = ()n n =( CTPT

3. Tnh trc tip t khi lng sn phm t chy:

M 44x 9y 14t

m

Do :

Sau khi bit c x, y, t v M ta suy ra z

II/Bi tp

Ngy: Bui: Dng 1: Xc nh CTPT HCHC khi ch cho PTK:Cu 1: Mt hp cht hu c A c M = 74. t chy A bng oxi thu c kh CO2 v H2O. C bao nhiu cng thc phn t ph hp vi A?

A. 4.

B. 2.

C. 3.

D. A.1.

PP gii bi tp tm cng thc PT khibit khi lng phn t M

Bc 1 : t CTTQ : CxHyOzNtBc 2: Lp phng trnh a s: M= 12x + y + 16z +14t

( Thng l 12x + y + 16z = M

Nu l * => Bc 1: cz < M => min gi ch ca z

Bc 2 : Xt z tm ra x v y => CTPT

0 < y 2x + 2 +t Thng l 0 < y 2x + 2 i vi CxHyOz

=> y lun chn Gii bi trn

Xt z = 1 => C4H10O

Xt z = 2 ( => x = 3 => y = 6 => C3H6O2

Xt z = 3 ( 12x +y = 26 ( y = 26 12x

=> C2H2O3

=> 3 cng thc tha mn => C

Cu 2: Mt hp cht hu c A c t khi so vi khng kh bng bng 2. t chy hon ton A bng kh O2 thu c CO2 v H2O. C bao nhiu cng thc phn t ph hp vi A ?

A. 2.

B. A. 1. C. 3.

D. 4.

Xt z = 1 => x = 3 => y = 6 => C3H6O

Xt z = 2 => x = 2

y = 2 => C2H2O2

Xt z = 3 => 12x + y = 10 => loi v x = 0

2 cng thc phn t ph hp => A Dng 2: Xc nh CTPT HCHC khi cho % khi lng cc cht:

Cu 1: Hp cht X c %C = 54,54% ; %H = 9,1%, cn li l oxi. Khi lng phn t ca X bng 88. CTPT ca X l:

A. C4H10O.

B. C5H12O.

C. C4H10O2.

D. C4H8O2.

CT : C4H8O2 => D

Cu 2: Phn tch hp cht hu c X thy c 3 phn khi lng cacbon li c 1 phn khi lng hiro, 7 phn khi lng nit v 8 phn lu hunh. Trong CTPT ca X ch c 1 nguyn t S, vy CTPT ca X l

A. CH4NS.

B. C2H2N2S.

C. C2H6NS.

D. CH4N2S.

Chn 1 phn l 1g => mC = 3g ; mH = 1 g ; mN = 7g ; mS = 8g

=> CTDDGN (CH4N2S)n

V c 1 nguyn t S => n = 1 => CTPT : CH4N2S => D 3: t chy hon ton 0,92 g HCHC thu c 1,76 g CO2 v 1,08 g H2O. Xc nh % khi lng mi nguyn t trong HCHC.

4: t chy hon ton 7,75 g vitamin C (cha C, H, O) thu c 11,62 g CO2 v 3,17 g H2O. Xc nh % khi lng mi nguyn t trong phn t vitamin C.5: Oxi ho hon ton 0,6 g HCHC A thu c 0,672 lt kh CO2 ( ktc) v 0,72 g H2O. Tnh thnh phn phn trm ca cc nguyn t trong phn t cht A.6: Mt hp cht hu c gm C, H, O ; trong cacbon chim 61,22% v khi lng. Cng thc phn t ca hp cht l:

A. C3H6O2.

B. C2H2O3.

C. C5H6O2.

D. C4H10O.

HD:

M = 12x/0,6122 = 19,6x nguyn => x=5=> C7: Cht hu c X c M = 123 v khi lng C, H, O v N trong phn t theo th t t l vi

72 : 5 : 32 : 14. CTPT ca X l:

A. C6H14O2N.

B. C6H6ON2.

C. C6H12ON.

D. C6H5O2N.

=> D

8: Nilon 6, loi t nilon ph bin nht c 63,68% C; 9,08 % H; 14,14% O; v 12,38% N. Xc nh CTGN ca nilon 6. 9: Kt qu phn tch cc nguyn t trong nicotin nh sau: 74% C; 8,65% H; 17,35% N. Xc nh CTGN ca nicotin, bit nicotin c khi lng mol phn t l 162.

10: T tinh du hi, ngi ta tch c anetol mt cht thm c dng sn xut ko cao su. Anetol c khi lng mol phn t bng 148 g/mol. Phn tch nguyn t cho thy, anetol c %C = 81,08%; %H = 8,10% cn li l oxi. Lp CTGN v CTPT ca anetol.11: Hp cht X c phn tm khi lng C, H, O ln lt bng 54,54%; 9,10% v 36,36%. Khi lng mol phn t ca X bng 88. Xc nh CTPT ca X.12: T tinh du chanh ngi ta tch c cht limonen thuc loi hirocacbon c hm lng nguyn t H l 11,765%. Hy tm CTPT ca limonen, bit t khi hi ca limonen so vi heli bng 34.Dng 3 : Xc nh CTPT HCHC khi cho khi lng cc chttrong sn phm chy:

Dng 3.a: Cho SP chy di dang th tch hoc khi lng:

Cu 1:a):t chy hon ton hn hp X gm 3 hircacbon th thu c 2,24 lt CO2 v 2,72 gam nc. Th tch O2 cn cho phn ng l?

A. 5.6 B.4.48.

C. 6.72

D. 3.92 b)t chy hon ton 0,6 gam hp cht hu c X ri cho sn phm chy qua bnh ng dung dch Ca(OH)2 d thy c 2 gam kt ta v khi lng bnh tng thm 1,24 gam. T khi ca X so vi H2 bng 15. CTPT ca X l:

A. C2H6O.

B. CH2O.

C. C2H4O.

D. CH2O2.

Phng php gii : Tm khi lng tng nguyn t trong X C , H , O

Ta c M = 15.2 = 30 T khi vi H2 = 15 => n = 1 => CH2O => B

Cu 2: Khi t 1 lt kh X cn 6 lt O2 thu c 4 lt CO2 v 5 lt hi H2O (cc th tch kh o cng iu kin nhit , p sut). CTPT ca X l:

A. C4H10O.

B. C4H8O2.

C. C4H10O2.

D. C3H8O.

A: D

Cu 3: t chy hon ton 3 gam hp cht hu c X thu c 4,4 gam CO2 v 1,8 gam H2O. Bit t khi ca X so vi He (MHe = 4) l 7,5. CTPT ca X l:

A. CH2O2.

B. C2H6.

C. C2H4O.

D. CH2O.

X l CH2O => D

Cu 4: t chy 1 lt hi hirocacbon vi mt th tch khng kh (lng d). Hn hp kh thu c sau khi hi H2O ngng t c th tch l 18,5 lt, cho qua dung dch KOH d cn 16,5 lt, cho hn hp kh i qua ng ng photpho d th cn li 16 lt. Xc nh CTPT ca hp cht trn bit cc th tch kh o cng iu kin nhit , p sut v O2 chim 1/5 khng kh, cn li l N2.

A. C2H6.

B. C2H4.

C. C3H8.

D. C2H2.

Phn tch :18,5 lt ch cha CO2 v khng kh V H2O b ngng t

16,5 lt ch cha khng kh V CO2 b hp th bi kim => V CO2 = 18,5 16,5 = 2 lt

=> x = VCO2 / VX = 2

16 lt l N2 V O2 b hp th bi P d P P + O2 => P2O5 => VO2 d = 16,5 16 = 0,5 lt

16 lt N2 => V khng kh = 16.5 / 4 = 20 lt V N2 chim 4 /5 do oxi chim 1/5

=> V O2 ban u = 4 lt => VO2 p = VO2 ban u VO2 d = 4 0,5 = 3,5 lt

=> x + y/ 4 = VO2 p / VX = 3,5 = 2 + y/4 => y = 6 => C2H6 => A

Cu 5: t 0,15 mol mt hp cht hu c thu c 6,72 lt CO2 (ktc) v 5,4 gam H2O. Mt khc t 1 th tch hi cht cn 2,5 th tch O2. Cc th tch o cng iu kin nhit , p sut. CTPT ca hp cht l:

A. C2H6O2.

B. C2H6O.

C. C2H4O2.

D. C2H4O.

AD CT bi 66: => x = nCO2 / nX = 0,3 / 0,15 = 2 ; y = 2nH2O / nX = 0,6 / 0,15 = 4

t 1 th tch hi cht cn 2,5 th tch O2 => x + y/4 z/2 = VO2 /VX = 2,5

( 2 + 4/4 z/2 = 2,5 => z = 1 => C2H4O => D Dng 3.b: Sn phm chy vo bnh ng dd Ba(OH)2 hoc Ca(OH)2:Cu 6: t chy hon ton mt hp cht hu c X (C, H, N) bng lng khng kh va (gm 1/5 th tch O2, cn li l N2) c kh CO2 , H2O v N2. Cho ton b sn phm chy qua bnh ng dung dch Ba(OH)2 d thy c 39,4 gam kt ta, khi lng dung dch gim i 24,3 gam. Kh thot ra khi bnh c th tch 34,72 lt (ktc). Bit < 2. CTPT ca X l:

A. C2H7N.

B. C2H8N.

C. C2H7N2.

D. C2H4N2.

Trong trng hp d kien cho: hap thu toan bo san pham chay vao dung dch ... d thu c m gam ket tua ong thi khoi lng dung dch giam n gam: Th = n( va m( - (+ )= (mgiam

Nen t ay ta co: mH2O = m( - ((mgiam +mCO2)

A ngCu 21 : t chy hon ton 0,12 mol cht hu c X mch h cn dng 10,08 lt kh O2 (ktc). Dn ton b sn phm chy (gm CO2, H2O v N2) qua bnh ng dung dch Ba(OH)2 d, thy khi lng bnh tng 23,4 gam v c 70,92 gam kt ta. Kh thot ra khi bnh c th tch 1,344 lt (ktc). Cng thc phn t ca X l:

A. C2H5O2N.

B. C3H5O2N.

C. C3H7O2N.

D. C2H7O2N.

=> C

Cu 7: Oxi ha hon ton 4,02 gam mt hp cht hu c X ch thu c 3,18 gam Na2CO3 v 0,672 lt kh CO2. CTGN ca X l:

A. CO2Na.

B. CO2Na2.

C. C3O2Na.

D. C2O2Na.

=> A

Cu 8: t chy hon ton mt hirocacbon trong 0,5 lt hn hp ca n vi CO2 bng 2,5 lt O2 thu c 3,4 lt kh. Hn hp ny sau khi ngng t ht hi nc cn 1,8 lt, tip tc cho hn hp kh cn li qua dung dch kim d th cn li 0,5 lt kh. Cc th tch c o cng iu kin nhit , p sut. CTPT ca hirocacbon l:

A. C4H10.

B. C3H8.

C. C4H8.

D. C3H6.

Hn hp 3,4 lt kh gm O2 d C th c ; CO2To thnh + d v H2O

1,8 lt l CO2 v O2 d v H2O b ngng t => VH2O = 3,4 1,8 = 1,6 lt

0,5 lt kh l O2d v CO2 b kim d hp th => VCO2 sau p = 1,8 0,5 = 1,3 lt

=> V O2 p = 2 lt Ch c hidrocabon CxHy p vi O2

Gi a , b ln lt l VCxHy v CO2 trc p

a + b = 0,5 lt

(1)

(x +y/4) = VO2 p /VCxHy = 2 / a ( a (x + y/4) = 2

(2) CT bi 66

VCO2 sau p = x. VCxHy + VCO2 trc p = xa + b = 1,3 lt =>ax = 1,3 - b

(3) BTNT C

y = 2VH2O / VCxHy = 3,2 / a ( ay = 3,2

(4) BTNT H

Ly 3 , 4 th vo 2 => b = 0,1 th vo 1 => a = 0,4 => th vo 3 v 4 => x = 3 ; y = 8 => C3H8 => B

Cu 9: t chy hon ton 1,605 gam hp cht hu c A thu c 4,62 gam CO2 ; 1,215 gam H2O v 168 ml N2 (ktc). T khi hi ca A so vi khng kh khng vt qu 4. Cng thc phn t ca A l:

A. C5H5N.

B. C6H9N.

C. C7H9N.

D. C6H7N.

=> CTPT A: C7H9N

Cu 10: Oxi ha hon ton 6,15 gam hp cht hu c X thu c 2,25 gam H2O ; 6,72 lt CO2 v 0,56 lt N2 (kc). Phn trm khi lng ca C, H, N v O trong X ln lt l:

A. 58,5% ; 4,1% ; 11,4% ; 26%.

Cu 11: Phn tch 0,31gam hp cht hu c X ch cha C, H, N to thnh 0,44 gam CO2. Mt khc, nu phn tch 0,31 gam X ton b N trong X chuyn thnh NH3 ri dn NH3 va to thnh vo 100 ml dung dch H2SO4 0,4M th phn axit d c trung ha bi 50 ml dung dch NaOH 1,4M. Bit 1 lt hi cht X (ktc) nng 1,38 gam. CTPT ca X l:

A. CH5N.

B. C2H5N2.

C. C2H5N.

D. CH6N.

A . CH5N

Cu 12: t chy 200 ml hi mt hp cht hu c X cha C, H, O trong 900 ml O2, th tch hn hp kh thu c l 1,3 lt. Sau khi ngng t hi nc ch cn 700 ml. Tip theo cho qua dung dch KOH d ch cn 100 ml kh bay ra. Cc th tch kh o cng iu kin nhit , p sut. CTPT ca Y l:

A. C3H6O.

B. C3H8O2.

C. C3H8O.

D. C3H6O2.

CT PT : C3H6O => A

Cu 13: Phn tch 1,5 gam cht hu c X thu c 1,76 gam CO2 ; 0,9 gam H2O v 112 ml N2 o 0oC v 2 atm. Nu ha hi cng 1,5 gam cht X 127o C v 1,64 atm ngi ta thu c 0,4 lt kh cht X. CTPT ca X l:

A. C2H5ON.

B. C6H5ON2.

C. C2H5O2N.

D. C2H6O2N.

=> C

Cu 14: t chay hoan toan mt th tich hi hp cht hu c A cn 10 th tich oxi (o cung iu kin nhit v p sut), san phm thu c chi gm CO2 va H2O vi mCO2 : mH2O = 44 : 9. Bit MA < 150. A co cng thc phn t la:

A. C4H6O.

B. C8H8O.

C. C8H8.

D. C2H2.

=> C

Cu 15: Cho 400 ml mt hn hp gm nit v mt hirocacbon vo 900 ml oxi (d) ri t. Th tch hn hp thu c sau khi t l 1,4 lt. Sau khi cho nc ngng t cn 800 ml hn hp, ngi ta cho li qua dung dch KOH thy cn 400 ml kh. Cc th tch kh u o cng iu kin nhit , p sut. Cng thc phn t ca cht hu c l:

A. C3H8.

B. C2H4.

C. C2H2.

D. C2H6.

Tng t bi 76 => VH2O b ngng t = 1,4 0,8 = 0,6 lt ;

V CO2 b hp th = 0,8 0,4 = 0,4 lt

Mo: p n => CTPT : CxHy V ch cha C v H => x :y = nC : nH = nCO2 : 2nH2O hay VCO2 : 2VH2O = 0,4 : 1,2 = 1 : 3 => CTGN : (CH3)n => vi n = 2 => C2H6 => D Ch D tha mn t l 1 : 3

Mo khc. Ta c VH2O = 0,6 lt ; VCO2 = 0,4 lt v Vhidrocacbon < 0,4 lt

Vhidrocabon = 0,2 lt Bi s chung ca VH2O v VCO2 Hoc l s VH2O v VCO2 chia ht

x = VCO2 / VX = 0,4 / 0,2 = 2 ; y = 2VH2O / VX = 2.0,6 / 0,2 = 6 => C2H6

Cu 16: t chy 0,279 gam hp cht hu c X, cho sn phm i qua cc bnh ng CaCl2 khan v KOH d. Thy bnh ng CaCl2 tng thm 0,189 gam cn bnh ng KOH tng thm 0,792 gam. Mt khc nu t chy 0,186 gam cht X th thu c 22,4 ml kh N2 ( ktc). Bit rng hp cht X ch cha mt nguyn t nit. Cng thc phn t ca hp cht X l:

A. C6H6N2.

B. C6H7N.

C. C6H9N.

D. C5H7N.

=> B ng :V c 1 N

Cu 17: t chy hon ton hp cht hu c cha C, H, Cl sinh ra 0,22 gam CO2, 0,09 gam H2O. Mt khc khi xc nh clo trong hp cht bng dung dch AgNO3 ngi ta thu c 1,435 gam AgCl. T khi hi ca hp cht so vi hiro bng 42,5. Cng thc phn t ca hp cht l:

A. CH3Cl.

B. C2H5Cl.

C. CH2Cl2.

D. C2H4Cl2.

Cch 1: Mo : bi t khi hi ca hp cht so vi hidro bng 42,5 => MX = 42,5 . 2 = 85

Ch c p n C c M = 85 => C

Cu 18: t chy hon ton 0,4524 gam hp cht A sinh ra 0,3318 gam CO2 v 0,2714 gam H2O. un nng 0,3682 gam cht A vi vi ti xt chuyn tt c nit trong A thnh amoniac, ri dn kh NH3 vo 20 ml dung dch H2SO4 0,5 M. trung ho axit cn d sau khi tc dng vi NH3 cn dng 7,7 ml dung dch NaOH 1M. Bit MA= 60. Cng thc phn t ca A l:

A. CH4ON2.

B. C2H7N.

C. C3H9N.

D. CH4ON.

Cch 1 : Mo => cho MA = 60 => Ch c p n A c M = 60 => A

Cu 19: t chy hon ton 0,01 mol cht hu c X cn va 0,616 lt O2. Sau th nghim thu c hn hp sn phm Y gm : CO2, N2 v hi H2O. Lm lnh ngng t hi H2O ch cn 0,56 lt hn hp kh Z (c t khi hi vi H2 l 20,4). Bit th tch cc kh u o ktc. Cng thc phn t X l:

A. C2H5ON.B. C2H5O2N.

C. C2H7O2N.

D. A hoc C.

=> D

Cu 20: X la mt ancol no, mach h. t chay 0,05 mol X cn 4 gam oxi. X co cng thc l:

A. C3H5(OH)3.

B. C3H6(OH)2.C. C2H4(OH)2.

D. C4H8(OH)2.

i vi dng bi ton ancol no c s C bng s nhm OH CTTQ: CnH2n+2 - n(OH)n ca ru m khi cho nX v nO2

Nu ta ly nO2 / nX = n + 0,5 ; => Nu chia nO2 / nX = 2,5 => C2H4(OH)2 ; = 3,5 => C3H5(OH)3

Ta c nO2 / nX = 2,5 => X c cng thc C2H4(OH)2

Cng thc rt ra t p : khi s C bng nhm OH => s C bng s O

CT TQ: CnH2n+2On V ancol nol

PT : CnH2n+2On + (2n+1)/2O2 => nCO2 + (n+1)H2O

nO2 / nCnH2n+2On = (2n+1)/2 = n + 0,5

Khng c th dng mo c : Ta c x + y/4 z/2 = nO2 / nX

Thay tng p n.

=> C : C2H6O2 c x = 2 ; y = 6 ; z = 2 => x + y/4 z/2 = 2,5 Tha mn => C ng

Cu 22: t chy hon ton 0,1 mol cht X cn 6,16 lt kh O2 (ktc), thu c 13,44 lt (ktc) hn hp CO2, N2 v hi nc. Sau khi ngng t ht hi nc, cn li 5,6 lt kh (ktc) c t khi so vi hiro l 20,4. Cng thc phn t ca X l:

A. C2H7O2N.

B. C3H7O2N.

C. C3H9O2N.

D. C4H9N.

=> ch c A ng

Cu 23: t chy hon ton 1,18 gam cht Y (CxHyN) bng mt lng khng kh va . Dn ton b hn hp kh sau phn ng vo bnh ng dung dch Ca(OH)2 d, thu c 6 gam kt ta v c 9,632 lt kh (ktc) duy nht thot ra khi bnh. Bit khng kh cha 20% oxi v 80% nit v th tch. Cng thc phn t ca Y l:

A. C2H7N.

B. C3H9N.

C. C4H11N.

D. C4H9N.

=> B

Cu 24: Phn tch 1,47 gam cht hu c Y (C, H, O) bng CuO th thu c 2,156 gam CO2 v lng CuO gim 1,568 gam. CTGN ca Y l:

A. CH3O. (31)

B. CH2O. (30)

C. C2H3O. (43)D. C2H3O2. (59)

=> B

Cu 25 : Mt hp cht hu c Y khi t chy thu c CO2 v H2O c s mol bng nhau v lng oxi cn dng bng 4 ln s mol ca Y. Cng thc phn t ca Y l:

A. C2H6O.

B. C4H8O.

C. C3H6O.

D. C3H6O2.

=> C ng

Cu 26 : t chy hon ton 0,2 mol mt axit cacboxylic no 2 ln thu c 1,2 mol CO2. Cng thc phn t ca axit l:

A. C6H14O4.

B. C6H12O4.

C. C6H10O4.

D. C6H8O4.

=> C ng

Cu 27 : t chy hon ton 5,8 gam mt hp cht hu c n chc X cn 8,96 lt kh O2 (ktc), thu c CO2 v H2O c s mol bng nhau. CTGN ca X l:

A. C2H4O.

B. C3H6O.

C. C4H8O.

D. C5H10O.

=> B

Cu 28: t chay hoan toan 0,2 mol hirocacbon X. Hp thu toan b san phm chay vao nc vi trong c 20 gam kt tua. Loc bo kt tua ri un nong phn nc loc lai co 10 gam kt tua na. Vy X khng th la:

A. C2H6.

B. C2H4.

C. CH4.

D. C2H2.

. p n C sai v c 1 C .

Cu 29: Hn hp X gm mt s hirocacbon l ng ng k tip. Tng khi lng phn t ca cc hirocacbon trong A l 252, trong khi lng phn t ca hirocacbon nng nht bng 2 ln khi lng phn t ca hirocacbon nh nht. Cng thc phn t ca hirocacbon nh nht v s lng hirocacbon trong X l:

A. C3H6 v 4.

B. C2H4 v 5.

C. C3H8 v 4.

D. C2H6 v 5.

=> A

Cu 30: t chy hon ton 5,80 gam cht X thu c 2,65 gam Na2CO3 ; 2,26 gam H2O v 12,10 gam CO2. Cng thc phn t ca X l:

A. C6H5O2Na.

B. C6H5ONa.

C. C7H7O2Na.

D. C7H7ONa.

=> B ng A l 6 : 5 : 2

Cu 31: t chy hon ton 1,88 gam hp cht hu c Z (cha C, H, O) cn 1,904 lt kh O2 (ktc), thu c CO2 v H2O vi t l mol tng ng l 4 : 3. Cng thc phn t ca Z l:

A. C4H6O2.

B. C8H12O4.

C. C4H6O3.

D. C8H12O5.

Cch 1: Vn ly 1,88 chia cho M cc p n => D tha mn

Cch 2: T l mol CO2 : nH2O = 4 : 3 => Chn nCO2 = 4x => nH2O = 3x Mnh thng lm zy quy v PT 1 n

BT khi lng : mZ + mO2 = mCO2 + mH2O ( 1,88 + 0,085.32 = 4x.44 + 3x.18 ( x = 0,02

nC = CO2 = 4x = 0,08 ; nH = 2nH2O = 2.3x = 0,12;

BT NT Oxi : nO(Z) + 2nO2 = 2nCO2 + nH2O ( nO + 2.0,085 = 2.0,08 + 0,06 ( nO = 0,05

x :y : z = nC : nH : nO = 0,08 : 0,12 : 0,05 = 8 : 12 : 5 => D tha mn.

Cu 32: Cho hirocacbon A v oxi (oxi c ly gp i lng cn thit t chy hon ton A) vo bnh dung tch 1 lt 406o5K v p sut 1at. Sau khi t p sut trong bnh (o cng nhit ) tng 5%, lng nc thu c 0,162g.

A. C2H6

B. C3H6

C. C4H8 D. C4H10

E. Kt qu khc.

Cu 33: t chy hon ton 1,12 lt (ktc) mt hirocacbon (A). Ton b sn phm hp th vo dd Ba(OH)2 d, to ra 29,55g kt ta v khi lng dd gim 19,35g. Vy CTPT ca (A) l:A. C2H2 B. C2H6C. C3H4 D. C3H6

E. C3H8.

Bi 34: t chy hon ton 5,6 g HCHC A thu c 13,2 g CO2 v 3,6 g H2O. T khi ca A so vi H2 l 28. Xc nh CTPT ca A.Bi 35: t chy hon ton 0,30 g cht A (cha C, H, O) thu c 0,44 g CO2 v 0,18 g H2O. Th tch hi ca ca 0,30 g cht A bng th tch ca 0,16g kh oxi ( cng k v nhit v p sut). Xc nh CTPT ca cht A.A. C2H6O.

B. CH2O.

C. C2H4O.

D. CH2O2.

Cu 36: Khi t 1 lt kh X cn 6 lt O2 thu c 4 lt CO2 v 5 lt hi H2O (cc th tch kh o cng iu

kin nhit , p sut). CTPT ca X l

A. C4H10O.

B. C4H8O2.

C. C4H10O2.

D. C3H8O.

Cu 37: t chy hon ton 3 gam hp cht hu c X thu c 4,4 gam CO2 v 1,8 gam H2O. Bit t khi

ca X so vi He (MHe = 4) l 7,5. CTPT ca X l

A. CH2O2.

B. C2H6.

C. C2H4O.

D. CH2O.

Cu 38: t chy 1 lt hi hirocacbon vi mt th tch khng kh (lng d). Hn hp kh thu c sau khihi H2O ngng t c th tch l 18,5 lt, cho qua dung dch KOH d cn 16,5 lt, cho hn hp kh i qua ng ng photpho d th cn li 16 lt. Xc nh CTPT ca hp cht trn bit cc th tch kh o cng iu kin nhit , p sut v O2 chim 1/5 khng kh, cn li l N2.

A. C2H6.

B. C2H4.

C. C3H8.

D. C2H2.

Cu 39: t 0,15 mol mt hp cht hu c thu c 6,72 lt CO2 (ktc) v 5,4 gam H2O. Mt khc t 1 th tch hi cht cn 2,5 th tch O2. Cc th tch o cng iu kin nhit , p sut. CTPT ca hp cht l

A. C2H6O2.

B. C2H6O.

C. C2H4O2.

D. C2H4O.

Cu 40: t chy hon ton mt hp cht hu c X (C, H, N) bng lng khng kh va (gm 1/5 th

tch O2, cn li l N2) c kh CO2 , H2O v N2. Cho ton b sn phm chy qua bnh ng dung dch

Ba(OH)2 d thy c 39,4 gam kt ta, khi lng dung dch gim i 24,3 gam. Kh thot ra khi bnh c th

tch 34,72 lt (ktc). Bit d X O 2 < 2. CTPT ca X l

A. C2H7N.

B. C2H8N.

C. C2H7N2.

D. C2H4N2.

Cu 41: Oxi ha hon ton 4,02 gam mt hp cht hu c X ch thu c 3,18 gam Na2CO3 v 0,672 lt kh

CO2. CTGN ca X l

A. CO2Na.

B. CO2Na2.

C. C3O2Na.

D. C2O2Na.

Cu 42: t chy hon ton mt hirocacbon trong 0,5 lt hn hp ca n vi CO2 bng 2,5 lt O2 thu c

3,4 lt kh. Hn hp ny sau khi ngng t ht hi nc cn 1,8 lt, tip tc cho hn hp kh cn li qua dung

dch kim d th cn li 0,5 lt kh. Cc th tch c o cng iu kin nhit , p sut. CTPT ca

hirocacbon l

A. C4H10.

B. C3H8.

C. C4H8.

D. C3H6.

Cu 43: t chy hon ton 1,605 gam hp cht hu c A thu c 4,62 gam CO2 ; 1,215 gam H2O v 168ml N2 (ktc). T khi hi ca A so vi khng kh khng vt qu 4. Cng thc phn t ca A l

A. C5H5N.

B. C6H9N.

C. C7H9N.

D. C6H7N.

Cu 44: Oxi ha hon ton 6,15 gam hp cht hu c X thu c 2,25 gam H2O ; 6,72 lt CO2 v 0,56 lt N2 (kc). Phn trm khi lng ca C, H, N v O trong X ln lt l

Cu 45: Phn tch 0,31gam hp cht hu c X ch cha C, H, N to thnh 0,44 gam CO2. Mt khc, nu

phn tch 0,31 gam X ton b N trong X chuyn thnh NH3 ri dn NH3 va to thnh vo 100 ml dung dch H2SO4 0,4M th phn axit d c trung ha bi 50 ml dung dch NaOH 1,4M. Bit 1 lt hi cht X (ktc) nng 1,38 gam. CTPT ca X l

Cu 46: t chy 200 ml hi mt hp cht hu c X cha C, H, O trong 900 ml O2, th tch hn hp kh thu

c l 1,3 lt. Sau khi ngng t hi nc ch cn 700 ml. Tip theo cho qua dung dch KOH d ch cn 100

ml kh bay ra. Cc th tch kh o cng iu kin nhit , p sut. CTPT ca Y l

A. C3H6O. B. C3H8O2. C. C3H8O. D. C3H6O2.

Cu 47: Phn tch 1,5 gam cht hu c X thu c 1,76 gam CO2 ; 0,9 gam H2O v 112 ml N2 o 0oC v 2

atm. Nu ha hi cng 1,5 gam cht Z 127o C v 1,64 atm ngi ta thu c 0,4 lt kh cht Z. CTPT ca X

l

A. C2H5ON.

B. C6H5ON2.

C. C2H5O2N.

D. C2H6O2N.

Cu 48: t chy hon ton mt th tch hi hp cht hu c A cn 10 th tch oxi (o cng iu kin nhit

v p sut), sn phm thu c ch gm CO2 v H2O vi mCO2 : mH2O = 44 : 9. Bit MA < 150. A c

cng thc phn t l

A. C4H6O.

B. C8H8O.

C. C8H8.

D. C2H2.

Cu 49: Cho 400 ml mt hn hp gm nit v mt hirocacbon vo 900 ml oxi (d) ri t. Th tch hn

hp thu c sau khi t l 1,4 lt. Sau khi cho nc ngng t cn 800 ml hn hp, ngi ta cho li qua

dung dch KOH thy cn 400 ml kh. Cc th tch kh u o cng iu kin nhit , p sut. Cng thc

phn t ca cht hu c l

A. C3H8.

B. C2H4.

C. C2H2.

D. C2H6.

Cu 50: t chy 0,282 gam hp cht hu c X, cho sn phm i qua cc bnh ng CaCl2 khan v KOH

d. Thy bnh ng CaCl2 tng thm 0,194 gam cn bnh ng KOH tng thm 0,8 gam. Mt khc nu t

chy 0,186 gam cht X th thu c 22,4 ml kh N2 ( ktc). Bit rng hp cht X ch cha mt nguyn t

nit. Cng thc phn t ca hp cht X l

A. C6H6N2.

B. C6H7N.

C. C6H9N.

D. C5H7N.

Cu 51: t chy hon ton hp cht hu c cha C, H, Cl sinh ra 0,22 gam CO2, 0,09 gam H2O. Mt khc

khi xc nh clo trong hp cht bng dung dch AgNO3 ngi ta thu c 1,435 gam AgCl. T khi hi

ca hp cht so vi hiro bng 42,5. Cng thc phn t ca hp cht l

A. CH3Cl.

B. C2H5Cl.

C. CH2Cl2.

D. C2H4Cl2.

Cu 52: t chy hon ton 0,4524 gam hp cht A sinh ra 0,3318 gam CO2 v 0,2714 gam H2O. un nng

0,3682 gam cht A vi vi ti xt chuyn tt c nit trong A thnh amoniac, ri dn kh NH3 vo 20 ml

dung dch H2SO4 0,5 M. trung ho axit cn d sau khi tc dng vi NH3 cn dng 7,7 ml dung dch

NaOH 1M. Bit MA= 60. Cng thc phn t ca A l

A. CH4ON2.

B. C2H7N.

C. C3H9N.

D. CH4ON.

Cu 53*: t chy hon ton 0,01 mol cht hu c X cn va 0,616 lt O2. Sau th nghim thu c hn

hp sn phm Y gm : CO2, N2 v hi H2O. Lm lnh ngng t hi H2O ch cn 0,56 lt hn hp kh Z

(c t khi hi vi H2 l 20,4). Bit th tch cc kh u o ktc. Cng thc phn t X l

A. C2H5ON.

B. C2H5O2N.

C. C2H7O2N.

D. A hoc C.

Cu 54: X l mt ancol no, mch h. t chy 0,05 mol X cn 4 gam oxi. X c cng thc l

A. C3H5(OH)3.

B. C3H6(OH)2.

C. C2H4(OH)2.

D. C4H8(OH)2.

Cu 55: Khi t chy hon ton mt amin n chc X, thu c 16,80 lt kh CO2 ; 2,80 lt N2 (cc th tch

o ktc) v 20,25 gam H2O. CTPT ca X l

A. C4H9N.

B. C3H7N.

C. C2H7N.

D. C3H9N.

Cu 56: t chy hon ton m gam mt amin X bng lng khng kh va thu c 17,6 gam CO2, 12,6

gam H2O v 69,44 lt N2 (ktc). Gi thit khng kh ch gm N2 v O2 trong oxi chim 20% th tch khng

kh. X c cng thc l

A. C2H5NH2.

B. C3H7NH2.

C. CH3NH2.

D. C4H9NH2.

Cu 57: Trong mt bnh kn cha hi este no n chc h A v mt lng O2 gp i lng O2 cn thit

t chy ht A nhit 140oC v p sut 0,8 atm. t chy hon ton A ri a v nhit ban u, p

sut trong bnh lc ny l 0,95 atm. A c cng thc phn t l

A. C2H4O2.

B. C3H6O2.

C. C4H8O2.

D. C5H10O2.

Cu 58: t chy hon ton 0,12 mol cht hu c X mch h cn dng 10,08 lt kh O2 (ktc). Dn ton b

sn phm chy (gm CO2, H2O v N2) qua bnh ng dung dch Ba(OH)2 d, thy khi lng bnh tng 23,4

gam v c 70,92 gam kt ta. Kh thot ra khi bnh c th tch 1,344 lt (ktc). Cng thc phn t ca X l

A. C2H5O2N.

B. C3H5O2N.

C. C3H7O2N.

D. C2H7O2N.

9

Cu 90: t chy hon ton 0,1 mol mt ancol mch h ba ln cha mt lin kt ba trong gc hirocacbon

thu c 0,6 mol CO2. Cng thc phn t ca ancol l

A. C6H14O3.

B. C6H12O3.

C. C6H10O3.

D. C6H8O3.

Cu 91: t chy hon ton 1,18 gam cht Y (CxHyN) bng mt lng khng kh va . Dn ton b hn

hp kh sau phn ng vo bnh ng dung dch Ca(OH)2 d, thu c 6 gam kt ta v c 9,632 lt kh (ktc)

duy nht thot ra khi bnh. Bit khng kh cha 20% oxi v 80% nit v th tch. Cng thc phn t ca Y

l

A. C2H7N.

B. C3H9N.

C. C4H11N.

D. C4H9N.

Cu 92: Phn tch 1,47 gam cht hu c Y (C, H, O) bng CuO th thu c 2,156 gam CO2 v lng CuO

gim 1,568 gam. CTGN ca Y l

A. CH3O.

B. CH2O.

C. C2H3O.

D. C2H3O2.

Cu 93: t chy hon ton mt hp cht hu c n chc X thu c sn phm chy ch gm CO2 v H2O

vi t l khi lng tng ng l 44 : 27. Cng thc phn t ca X l

A. C2H6.

B. C2H6O.

C. C2H6O2.

D. C2H4O.

Cu 94: Mt hp cht hu c Y khi t chy thu c CO2 v H2O c s mol bng nhau v lng oxi cn

dng bng 4 ln s mol ca Y. Cng thc phn t ca Y l

A. C2H6O.

B. C4H8O.

C. C3H6O.

D. C3H6O2.

Cu 95: t chy hon ton 0,2 mol mt axit cacboxylic no 2 ln thu c 1,2 mol CO2. Cng thc phn t

ca axit l

A. C6H14O4.

B. C6H12O4.

C. C6H10O4.

D. C6H8O4.

Cu 96: t chy hon ton 5,8 gam mt hp cht hu c n chc X cn 8,96 lt kh O2 (ktc), thu c

CO2 v H2O c s mol bng nhau. CTGN ca X l

A. C2H4O.

B. C3H6O.

C. C4H8O.

D. C5H10O.

Cu 97: t chy hon ton 0,2 mol hirocacbon X. Hp th ton b sn phm chy vo nc vi trong

c 20 gam kt ta. Lc b kt ta ri un nng phn nc lc li c 10 gam kt ta na. Vy X khng th

l

A. C2H6.

B. C2H4.

C. CH4.

D. C2H2.

Cu 98: Hn hp X gm mt s hirocacbon l ng ng k tip. Tng khi lng phn t ca cc

hirocacbon trong A l 252, trong khi lng phn t ca hirocacbon nng nht bng 2 ln khi lng

phn t ca hirocacbon nh nht. Cng thc phn t ca hirocacbon nh nht v s lng hirocacbon

trong X l

A. C3H6 v 4.

B. C2H4 v 5.

C. C3H8 v 4.

D. C2H6 v 5.

Cu 99: t chy hon ton 5,80 gam cht X thu c 2,65 gam Na2CO3 ; 2,26 gam H2O v 12,10 gam CO2.

Cng thc phn t ca X l

A. C6H5O2Na.

B. C6H5ONa.

C. C7H7O2Na.

D. C7H7ONa.

Cu 100: t chy hon ton 1,88 gam hp cht hu c Z (cha C, H, O) cn 1,904 lt kh O2 (ktc), thu

c CO2 v H2O vi t l mol tng ng l 4 : 3. Cng thc phn t ca Z l

A. C4H6O2.

B. C8H12O4.

C. C4H6O3.

D. C8H12O5.

PAGE 11

_1188203050.unknown

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