PHẦN 1 GIỚI THIỆU CÁC CHUYÊN ĐỀ GIẢI NHANH BÀI TẬP HÓA HỌC CHUYÊN ĐỀ 1 : PHƯƠNG PHÁP ĐƯỜNG CHÉO I. Nguyên tắc: - Các giá trị trung bình như : Khối lượng mol trung bình; số cacbon trung bình; nồng độ mol trung bình; nồng độ % trung bình; số khối trung bình của các đồng vị… luôn có mối quan hệ với khối lượng mol; số cacbon; nồng độ mol; nồng độ %; số khối… của các chất hoặc nguyên tố bằng các “đường chéo”. - Trong phản ứng axit – bazơ : Thể tích của dung dịch axit, bazơ, nồng độ mol của H + , OH - ban đầu và nồng độ mol của H + , OH - dư luôn có mối quan hệ với nhau bằng các “đường chéo”. II. Các trường hợp sử dụng sơ đồ đường chéo 1. Trộn lẫn hai chất khí, hai chất tan hoặc hai chất rắn không tác dụng với nhau  ⇒                 − = = −       !"#$%!&'(!)*     !+!, !-,*     -./ !"-.#$%!&'(!)*  M -./!&01 !"-.!&01#$%! &'(!)* 2. Trộn lẫn hai dung dịch có cùng chất tan: 2&3$4-./ 4 !+!, 4 % 4 5%67!8"%9-./ .(3 4 * 2&3$:-./ : !+!, : % : 5 : ; 4 9-./.(3 : * 2&3$!&/-./< 4 = : !+!,< 4 = : %5 4 >> : 9#-. /.(3* ?#@!A!A#B.C.!/6 a. Đối với nồng độ % về khối lượng:  ⇒  : 4 : 4       − = − 549 b. Đối với nồng độ mol/lít:  ⇒  : 4 : 4       − = − 5:9 c. Đối với khối lượng riêng:  ⇒  : 4 : 4       − = − 5D9 3. Phản ứng axit - bazơ a. Nếu axit dư:  Page 1  4  :  E : E E 4 E  E : E E 4 E F  4  : 3 4 3 : E3 : 3E E3 4 3E 3                − − ⇒ 0 3&   0 3& GH = H    H   H  − + + +         =     −         !+!,3&3$I.!#0J*  0 GH −     %GH   07&*  0 H +      3& H +     %H =  07&#%H =  3* b. Nếu bazơ dư   ⇒ 0 3&   0 3& GH   GH    H = GH  − − + −     −     =             !+!,3&3$I.!#0J*  0 GH −      3& GH −     %GH   07&#GH   3*  0 H +     %H =  07&* III. Các ví dụ minh họa Ví dụ 1:K&'(!L-.!&01DMM*.#$0N DM  # DO  * 67P&'(!L DM   A. OM* B.:M* C.QR* D.:R* Hướng dẫn giải S63T! DO DM    DMM DM 4  DO DMM D − = = − ⇒P DM  < D *4RRP U <OMP* Đáp án A. Ví dụ 2: HC/6.-,KG#K : G!V-...#B..0W4XOM*VY"!+!,KG #K : G!C/67/! A.4D* B.D4* C.44* D.:D* Hướng dẫn giải  2 (NO,N O) M <4XOM*:<DDM S63T! : K G KG  DDM DR 4  UU DDM D − = = − Đáp án A. Ví dụ 3:%!C/6G : G D Z.N&-.Y!.(&&[!V-..#B..4Q*67 P#N!+!,G D !C/6 A.4MP* B.:MP* C.DMP* D.UMP* Hướng dẫn giải S63T Page 2  0 0 3& 3&  0 0 3&  H  GH H H   GH  H H + − + + − + +       +                 −        0 0 3& 3&  0 0 3&  H  GH GH GH   GH  H GH + − − − − + −       −                 +       ⇒ D : G G  U 4  4: D = = ⇒ D G 4 P D 4 = + ×4RRP<:MP* Đáp án B. Ví dụ 4:7!%.!+!,\!#B.%!!+!,]^\!+!&/C/6 -,!V-..#B..0W4M*^ A. D H Q * B. U H 4R * C. M H 4: * D. X H 4U * Hướng dẫn giải S63T ⇒ U : H :    DR :  4U 4 − = = ⇒ : −DR<:Q ⇒ : <MQ⇒4U=:<MQ⇒<U⇒^ U H 4R * Đáp án B. Ví dụ 5:HC/6.0^#I.!VY!A44R*_!'!C/6!( !&/C/6-,`*`a&3&3$H : ?G U "!&/C/6-,b!V-..#B..0W 4c*@!A6d!L^ A.  D H Q * B. D H X * C. U H Q * D. D H U * Hướng dẫn giải = Z M 38 ⇒bG : #  G : S63T! : : G G  UU DQ 4  DQ D: 4 − = = − efA  I H ' =5I= U y 9G : →IG : = : y H : G 044R 645I= U y 9I 6R4R5I= U y 9I ⇒4R5I= U y 9<I⇒UR<QI='⇒I<U#'<Q Đáp án C. Ví dụ 6:C/6K : H : #KH D !V-.#B..Q*2gC/6.a&3&3$H : ?G U " 3!1!+!,-,hi.%!L*6767!85P9!\!+!,C.-,!C/67/! A.:MPK : :MPH : #MRPKH D * B.:MPKH D :MPH : #MRPK : * C.:MPK : :MPKH D #MRPH : * D.4MPK : DMPH : #MRPKH D * Hướng dẫn giải j..a&3&3$H : ?G U "3!0%KH D 0$ 6!T3!67KH D MRP* : : D 5K H KH 9  <Q*:<4X S63T666! Page 3 D : G G   UQ D: DX  4Q : DX   D: UQ DX = − = × = = − U : H :  :   4X  DR  4M : DR    4X DR = − = × = = − : : D : : 5K H 9 KH 5H K 9  4X  4  4O 4X 4 − = = − ⇒ : : 5K H 9  <4M : : 5K H 9  <4M-./!&01C/6K : #H : *.k6!T63T666 !  : : H K  :Q 4M 4  4M : 4 − = = − ⇒PK : <PH : <:MP* Đáp án A. Ví dụ 7:HC/6K#K*C/6!3T#B.3&3$KG D 3!1!i-k!!-. /0W-./KG D l!.6fA*67P!\-./K!C /67& A.:MQUP* B.:OQUP* C.URUMP* D.:OUQP* Hướng dẫn giải K=KG D →↓=KKG D 549 K=KG D →↓=KKG D 5:9 j./-k!!5#90W-./KG D 3-./!&01. &.-k!! 3 AgCl AgBr AgNO M M 170 + = = # Cl ,Br M − − <4ORm4RQ<X:*H'-./!&01. &.07& NaCl,NaBr M <:D=X:<QM S63T666!  K K  4RD QM 4Q  QM MQM :XM − = = − ⇒ NaCl NaBr NaCl m 18.58,5 100% 27,84% m m (26,5.103) (18.58,5) = × = + + Đáp án B. Ví dụ 8:(:MR3&3$KGH:#:RR3&3$H D eG U 4M*&.!i!#-./ !A A.4U:K : HeG U nD:QK D eG U * B.:QUK : HeG U n4XUK D eG U * C.4:KH : eG U n:QUK : HeG U * D.:UKH : eG U n4U:K : HeG U * Hướng dẫn giải  D U KGH H eG  R:M : M 4 :  R: 4M D × < = = < × ⇒!iC/6:&.KH : eG U K : HeG U * ? ⇒ : U : U K HeG KH eG  :  4 = → : U : U K HeG KH eG  : =  : U : U D U K HeG KH eG H eG    RD + = =  ⇒ : U : U K HeG KH eG  R:   R4  =    =   ⇒ : U : U K HeG KH eG  R: 4U: :QU   R4 4:R 4:  = × =    = × =    Đáp án C. Page 4 : U 4 : U : M : K HeG  : 4 D D M  D M 4 KH eG  4 : D D = − = = = − = Ví dụ 9:Hh!D4XUC/6:&.G D #G D 0W3&3$H3!&/ UUQ-,G : 5-!9*67PG D !C/6 A.MRP* B.MMP* C.XRP* D.XMP* Hướng dẫn giải : G RUQQ  ::U = <RR:→ D4XU  RR: = <4MQ:* S63T ⇒ D G MQ: P MQ: DQQ = + ×4RRP<XRP* Đáp án C. Ví dụ 10:a&"\!.!AXRPo\ : G D *a&"\!.!AXcXPo\ D G U *%  ! a&"#B.   ! a&"!&/a&"!p4! a&"!+.N&k/RM! AUP0*VY   q   A.M:* B.DU* C.UD* D.:M* Hướng dẫn giải: ?-o\!4! C.a&" r&"A 5-9U:R 4XR 44: 4RRR 4RR XR =⋅⋅ r&"A 5-9MRU :D: 4XQ 4RRR 4RR XXc =⋅⋅ r&"A 5-9UQR 4RR U 4MRR =       −× ?   U:REMRUUQRE<:U UQR   MRUEU:RUQRE<XR ⇒ M : XR :U     ==  Đáp án D. Ví dụ 11:_+!&/3&3$H:MP7 ' 4 3&3$HUMP6#B. : 3&3$H 4MP*VY 4 q :  A.4:* B.4D* C.:4* D.D4* Hướng dẫn giải S63T@!A549 4 : UM :M  :R :  4M :M 4R 4 − = = = − * Đáp án C. Ví dụ 12:_+6/MRR3&3$B&..s5<RcP97 '3&3$ KDP6#B.B !*t.!$ A.4MR* B.:4UD* C.:QMO* D.DMR* Page 5 D 4 D : G 5 4cO9 4RR 4MQ: MQ:  4MQ: G 5 4RR9 4cO 4MQ: DQQ = − = = = − = Hướng dẫn giải  ⇒  4 < Rc MRR :4 Rc × + <4MR* Đáp án A. Ví dụ 13:Hh!:RR?G D # : 3&3$H : ?G U UcP!/3&3$H : ?G U  OQUP*t.!$ :  A.4DDD* B.4UXc* C.:O::* D.DRR* Hướng dẫn giải e!16fA ?G D =H : G→H : ?G U  4RR?G D → cQ 4RR QR × <4::MH : ?G U * K%3&3$H : ?G U !A4::MP* t). 4  : 7/!-./?G D #3&3$H : ?G U UcP7 '*\549! 4 : Uc OQU  :cU  4::M OQU UU4 − = = − ⇒ : UU4  :RR :cU = × <DRR* Đáp án D. Ví dụ 14: 7 '0.(&!.!+&?G U *MH : G#0.(&3&3$&?G U QP+ 6!:QR3&3$&?G U 4XPu A.4QR#4RR* B.DDR#:MR* C. XR#::R* D.UR#:UR* Hướng dẫn giải U : 4XR :MR &?G *MH G 1 2 3 1 44 2 4 43 →.&?G U *MH : G3&3$&?G U  P< 4XR 4RR :MR × = XUP* t). 4 -./&?G U *MH : G# : -./3&3$&?G U QP* \ ⇒ 4 :  Q 4  UQ X = = * "!- 4 = : <:QR* v'-./&?G U *MH : G  4 < :QR 4 4 X × + <UR #-./3&3$&?G U QP : <:QR−UR<:UR* Đáp án D. Ví dụ 15:70.(&,!I.!H : ?G U 52<4QU9#0.(&,!B !+6!c,!3& 3$H : ?G U 2<4:Qqu A.:,!#O,!*B.D,!#X,!*C.U,!#M,!*D.X,!#D,!* Hướng dẫn giải Page 6  4 5K9  : 5H : G9 Rc D R ERcRE EDRcE 4 : 5 9 XU Q 4X Q 4X 5 9 Q XU 4X UQ − = − = ?  ⇒ : : U H G H ?G  RMX :  R:Q 4 = = * "!- : H G  = : U H ?G  <c⇒ : H G  <X,!# : U H ?G  <D,!* Đáp án B. Ví dụ 16: %:MR3&3$AC/6HRRQ#H : ?G U RR4#B.:MR3&3$ KGHa!&/MRR3&3$6H<4:*t.!$a  A.R4D* B.R4:* C.R4U* D.R*4R* Hướng dẫn giải  K%H =  07&0WRRQ=RR4*:<R4* K%GH   07&0Wa* 2&3$&6fA6H<4:&'GH  36GH<:* K%GH   30W4R :  <RR4* S63T!/6GH  3! 0 3&   0 3& GH   GH    H = GH  − − + −     −     =         < RR4 4 R4: R4 RR4 4 a a − = ⇒ = + * Đáp án B. Ví dụ 17: %gD3&3$H : ?G U R4HKG D R:#HRD#B.w!+!,0W&!& /3&3$*x 'DRR3&3$6fA#B.V,!3&3$KGHR:# jGHR:c!&/3&3$6H<:*t.!$V A.R4DU,!* B.R:4U,!* C.RU4U,!* D.RU:U,!* Hướng dẫn giải K%H =  07&0W5R4*:*R4=R:*R4=RD*R49RD< RO D * K%GH   07&0Wn5R:=R:c9<RUc* 2&3$&6fA6H<:&'H = 3* K%H = 30W4R :  <RR4*  S63T!/6H = 3!  0 3&   0 3& GH = H    H   H  − + + +         =     −     < RUc RR4 RD R4DU RO RR4 D V V + = ⇒ = − * Đáp án A. Ví dụ 18: 2&3$HR:nHKG D RDnH : ?G U R4nHG U RD3&3$ jGH RDnKGHRUn5GH9 : R4M*7!%#!\!VY!+!,0.(&+/ 3&3$6H<4D A.44c* B.c44* C.4R4cc* D.cc4R4* Hướng dẫn giải  K%H =  07&0W5R:=RD=R4*:=RD9<4* K%GH   07&0W5RD=RU=R4M*:9<4* 2&3$&6fA6H<4D&'GH  36GH<4* K%GH   30W4R 4  <R4* Page 7 : : U H G  4 E4QU 4:Q E RMX 4:Q H ?G  4QU E4:Q 4E R:Q − = − = S63T!/6GH  3!  0 3&   0 3& GH   GH    H = GH  − − + −     −     =         < 4 R4 c 4 R4 44 − = + * Đáp án B. IV. Các bài tập áp dụng Câu 1: K&'(!L-.!&01XDMU*_.#$0N XD :c & # XM :c & * 67P&'(!L XD :c &  A.ODRP* B.DU:P* C.D:DP* D.:ORP* Câu 2: K&'(!L-.!&01DMM*!!y.(:#$ Cl DM # Cl DO *e7!8#N -./ DO 4O Cl A!HG U 5#B..#$ H 4 4 I.#$ O 4X Q 9.!$&d'u  A.c:RP* B.QcMP* C.cXOP* D.cURP* Câu 3: B.!!i..#$ 4 H# : H*.k!&'(!L-.!&01.4RRQnI. 4X*?&'(!L#$ : H!4B&'( !53<4q9 A.MMD*4R :R * B.MMD*4R :R * C.DDM*4R :R * D.UQM*4R :R * Câu 4: Hh!0W3&3$HKG D l!&/C/6-,KG#K : G!V-. #B.H : 0W4XOM*VY!+!,-,!C/6 A.:D* B.4:* C.4D* D.D4* Câu 5:Hh!!4:C/6o\&5!VY4490WI.!HKG D !&/,!5Z-!9C/6 -,^5KG#KG : 9#3&3$`5VA.&.#I.!39*V-.^.#B.H : 0W4c*t.!$  A.::U* B.UUQ* C.MXR* D.DDX* Câu 6:HC/6j,^K : #H : !z-..#B.H\4Q*_&^%!!..!01-, I{!!&/C/6-,`!z-..#B.H\:*H.Y&& !6fA!|/6KH D  A. :MP* B.MRP* C.XRP* D.OMP* Câu 7: (4MR3&3$jGH:#4:R3&3$H D eG U 4*j./&. !&/!3&3$ A.4RUUjH : eG U nQMj D eG U * B.4RUUj : HeG U n4:O:j D eG U * C.4RUUj : HeG U n4DMjH : eG U * D.4DMjH : eG U n4U:j D eG U * Câu 8:C/60%!b#o\#/33&3$&?G U *?&-.-k!!{6fA)0} 673&3$!&/0%!~*6767!8!\-./b!C/60%!0 7& A.QMDRP* B.cR:OP* C.Q::RP* D.4:XOP* Câu 9: Hh!:QUC/6:&.G D #G D 0W3&3$H539!&/ RXO:,!-,Z.N&-.Y!.(&&[*67PG D !C/6 A.DDDDP* B.UMMMP* C.MUUMP* D.XXXOP* Câu 10:-#v!&6.!AUMP& : G*-#v!!\.!AORP&G*7!% #!\!VY-./<    +/a&"!p4! a&"!+.N&k /!.RM! &'( !u A.MD B.MU C.UM D. DM Câu 11: p4! a&"\!.!.N&k/U:R-o\*p4! a&"\!.!.N&k /MRU-o\*H}.6f.!%.a&"!(#B.!VY-./5    90.(&+/4 ! a&"C/6!p4! a&"C/6'.N&k/UQR-o\*  A.4D* B.:M* C.:D* D.44* Câu 12: +!,B#3&3$?G U :7+6/4RR3&3$?G U RU7/! A.MR#MR* B.UR#XR* C. QR#:R* D.:R#QR* Câu 13:%!3&3$KGH%:#%!3&3$KGH-%RM*_+3&3$B. %4!176f.6k#N!+!,.w:3&3$!\!VY A. 4: B.:4 C.4D D.D4 Câu 14: %!3&3$H%DMP#%!3&3$H-%4MP*_+!&/3&3$ B.%:RP!176f.6k:3&3$'!\!VY-./ A. 4D* B.D4* C.4M*D.M4* Page 8 Câu 15: j./3&3$K4MP7!%#B.:RR3&3$KDRP+!&/3&3$ K:RP A.:MR* B.DRR* C.DMR* D. URR* Câu 16: Hh!!K : G&'( !#UR3&3$KGH4:P!&/3&3$ KGHM4P*t.!$ A. 44D* B.:RR* C.D4Q* D.URR* Câu 17: x/?G D 7!(#3&3$H : ?G U 4RP+/4RR3&3$H : ?G U :RP  A.:M* B.QQQ* C.XXX* D.:UM* Câu 18: +!,B&'( !7!(#4,!3&3$H : ?G U cQP53<4QUq9+/3&3$ B.%4RP A.4U4c:* B.4M4c:* C.4X4c:* D.4O4c:* Câu 19: 2&3$/&\!'.4DQ  35q90.(&u.k! 2 5 C H OH(ng.chÊt) d = 0,8 g/ml n : H G 3 4   = * A.RQRM* B.RQMM* C.RcO:*  D.Rc4M* Câu 20: %:MR3&3$AC/6HRRQ#H : ?G U RR4#B.:MR3&3$ jGH!&/MRR3&3$6H<4:*t.!$ A.R4D* B.R4:* C.R4U* D.R*4R* Câu 21:%gD3&3$H : ?G U R4HKG D R:#HRD#B.w!+!,0W&!& /3&3$*x 'UMR3&3$6fA#B.,!3&3$KGHR:# jGHR:c!&/3&3$6H<:*t.!$ A.R:R4,!* B.RD:4,!* C.RX:4,!* D.RXDX,!* Câu 22: +!,3&3$5GH9 : RR:M7#4RR3&3$C/6HKG D #H6H< 4+!&/3&3$6H<: A. R::U,!* B. R4M,!* C. RDDX,!* D. RUUQ,!* Câu 23:MR3&3$AC/6jGHRRM#5GH9 : RR:M.!!(3&3$H R4X#MR3&3$!(!&/3&3$B.6H<:*v'.!$ A. DXXO* B. DRDD* C.URUM*  D.UMXO* Câu 24: %4RR3&3$6H<4H#HKG D #B.4RR3&3$KGH%!&/ :RR3&3$6H<4:*t.!$5•H = €•GH  €<4R 4U 9 A. R4M* B. RDR*  C. RRD* D. R4:* Câu 25: %:RR3&3$AC/6HR4#H : ?G U RRM#B.DRR3&3$ 5GH9 : %q,!!&/-k!!#MRR3&3$6H<4D*t.!$# 7/!  A.R4M#:DD*  B.R4M#UUX* C.R:#DUcM* D.R:#:DD* Câu 26:%:MR3&3$C/6HRRQ#H : ?G U RR4#B.:MR3&3$5GH9 : % I!&/-k!!#MRR3&3$6H<4:*t.!$#I A.RMQ:M#RRX* B.RMMXM#RRX* C. RMQ:M#RRD* D.RMMXM#RRD* Câu 27:x '3&3$I.!6H<M#3&3$0J6H<c!\!VY+!&/3&3$6H< Qu A. c 44 = axit bazo V V * B. 44 c = axit bazo V V * C. 0J < I * D.j@I$/* Câu 28:2&3$HR:nHKG D RDnH : ?G U R4nHG U RD3&3$ jGH RDnKGHRUn5GH9 : R4M*7!%#!\!VY!+!,0.(&+/ 3&3$6H<4D A.44c* B.c44* C.4R4cc* D.cc4R4* Câu 29:_&C/6-,RRX : H : #RRUH : #B.I{!K.&%!!..!&/ C/6-,`*2g!0%C/6`%.!p!pa&01y3&3$0539!1hi.RUUQ,!C/6 -,b5-!9!V-.#B.G : RM*j./013&3$0!8 A.4:R* B. 4RU* C.4XU*D.4D:* Câu 30:%!5/&9A^a&01y&G539&*?&-.6fA !-./ !~!01.fRD:*HC/6.!&/!V-..#B..4MM* t.!$ Page 9 A.Rc:* B.RD:* C.RXU* D.RUX* Câu 31:C/6^.A-k!.k6&!3l']!3T#B.&G 539&!&/%!C/6~b#%!C/6.`5!V-..#B.H : 4DOM9*! 0%`6fA#B.%!/3 : G5"KG D 9!3&3$KH D &.XUQ*t. !$ A.OQ* B.OU* C.c:* D.QQ* Câu 32:C/6^. !w&•@!A6d!L : H O KG : !3T#p#B.3&3$ KGH#&!&/3&3$`#UUQ,!C/6b5Z-!9.-,5N&I. 'a&‚ [9*V-..b.#B.H : 0W4DOM*@i3&3$`!&/-./&.- A.4XM* B.4UD* C.Qc* D.4MO* CHUYÊN ĐỀ 2 : PHƯƠNG PHÁP BẢO TOÀN NGUYÊN TỐ VÀ BẢO TOÀN KHỐI LƯỢNG I. Phương pháp bảo toàn nguyên tố 1. Nội dung định luật bảo toàn nguyên tố: - Trong phản ứng hóa học, các nguyên tố luôn được bảo toàn. 2. Nguyên tắc áp dụng: Trong phản ứng hóa học, tổng số mol của nguyên tố trước và sau phản ứng luôn bằng nhau. 3. Các ví dụ minh họa: Ví dụ 1:_!'!URU%!C/60%!-.i.o\&!-@-, !&/McXC/6DI.!*Hh!k!C/6DI.!0W3&3$H:*,!+ !,3&3$H73•* A.RM,!* B.RO,!* C.R4:,!* D.4,!* Hướng dẫn giải  G < I.! − - <McX−URU<4c: G 4c:  R4:  4X = = Hh!k!C/60I.!0W3&3$H!i!H : G& :H = =G : − →H : G R:U←R4: ⇒ H R:U  R4: : = = ,! Đáp án C. Ví dụ 2:C/6b*_\I.!:QX0WI.3!&/ UUXC/6I.!*H!k!!3&3$H!&/3&3$2*@i3& 3$2/C/6&.- A.ccX* B.UcQ* C. OUO* D.4RRQ* Hướng dẫn giải t).-.i.i.3.Y0-.i.!(#B.!$ =  : G : → : G  549  : G  =:H→:  =H : G 5:9 \6!15495:9→ : H G  U* = S63T$&v!0f!-./→ : G  UUX :QX 4X = − =  Page 10 [...]... FexOy + yCO xFe + yCO2 Khớ thu c cú M = 40 gm 2 khớ CO2 v CO d n CO2 44 12 40 n CO 28 4 n CO2 3 %VCO2 = 75% = n CO 1 75 n CO ( p.ư ) = n CO2 = ì 0,2 = 0,15 mol nCO d = 0,05 mol Mt khỏc: 100 Thc cht phn ng kh oxit st l do CO + O (trong oxit st) CO2 nCO = nO = 0,15 mol mO = 0,15ì16 = 2,4 gam mFe = 8 2,4 = 5,6 gam nFe = 0,1 mol Theo phng trỡnh phn ng ta cú: n Fe x 0,1 2 = = = Fe2O3 n CO2 y 0,15... CO3 2 BaCO3 (1) 2+ 2 Ca + CO3 CaCO3 (2) Theo (1) v (2) c 1 mol BaCl 2, hoc CaCl2 bin thnh BaCO3 hoc CaCO3 thỡ khi lng mui gim (71 60) = 11 gam Do ú tng s mol hai mui BaCO3 v CaCO3 bng: 43 39,7 = 0,3 mol 11 m tng s mol CO3 2 = 0,1 + 0,25 = 0,35, iu ú chng t d CO3 2 Gi x, y l s mol BaCO3 v CaCO3 trong A ta cú: x + y = 0,3 197x + 100y = 39,7 x = 0,1 mol ; y = 0,2 mol Thnh phn ca A: 0,1 ì197 %m BaCO3... ban u l A 3,12 gam B 3,21 gam C 4 gam D 4,2 gam Hng dn gii t0 Fe3O4 + 4CO 3Fe + 4CO2 t0 CuO + CO Cu + CO2 CO2 + Ca(OH)2 CaCO3 + H2O CO ly oxi trong oxit CO2 nO (trong oxit) = nCO = n CO2 = n CaCO3 = 0,05 mol moxit = mkim loi + moxi trong oxit = 2,32 + 0,05.16 = 3,12 gam ỏp ỏn A Vớ d 17: Hn hp X gm Fe, FeO v Fe2O3 Cho mt lung CO i qua ng s ng m gam hn hp X nung núng Sau khi kt thỳc thớ nghim thu... dung dch hn hp Na 2CO3 0,1 mol/l v (NH4) 2CO3 0,25 mol/l Cho 43 gam hn hp BaCl2 v CaCl2 vo dung dch ú Sau khi cỏc phn ng kt thỳc ta thu c 39,7 gam kt ta A v dung dch B Tớnh % khi lng cỏc cht trong A A %m BaCO3 = 50%, %mCaCO3 = 50% B %m BaCO3 = 50,38%, %m CaCO3 = 49,62% C %m BaCO3 = 49,62%, %m CaCO3 = 50,38% D Khụng xỏc nh c Hng dn gii Trong dung dch: Na 2CO3 2Na+ + CO3 2 (NH4) 2CO3 2NH4+ + CO3 2 BaCl2 Ba2+... lớt CO (ktc) qua 16 gam Fe xOy nung núng Dn ton b lng khớ sau phn ng qua dung dch Ca(OH)2 d, thy to ra 30 gam kt ta Khi lng st thu c l A 9,2 gam B 6,4 gam C 9,6 gam D 11,2 gam Hng dn gii FexOy + yCO xFe + yCO2 1 y x y 8,96 nCO = = 0,4 (mol) 22,4 CO2 + Ca(OH)2 CaCO3 + H2O n CO2 = n CaCO3 = 30 = 0,3 (mol) 100 n CO > n CO2 CO d v FexOy ht Theo nh lut bo ton khi lng ta cú: Page 20 m Fex Oy + m CO =... to ca este l CH3OCOCOOCH3 ỏp ỏn B Vớ d 25: Thu phõn hon ton 11,44 gam hn hp 2 este n chc l ng phõn ca nhau bng dung dch NaOH thu c 11,08 gam hn hp mui v 5,56 gam hn hp ru Xỏc nh cụng thc cu to ca 2 este A HCOOCH3 v C2H5COOCH3 B C2H5COOCH3 v CH3COOC2H5 C HCOOC3H7 v C2H5COOCH3 D C B, C u ỳng Hng dn gii t cụng thc trung bỡnh tng quỏt ca hai este n chc ng phõn l RCOOR RCOOR + NaOH RCOONa + ROH 11,44... Phn trm khi lng Fe2O3 trong hn hp A l A 86,96% B 16,04% C 13,04% D 6,01% Hng dn gii 0,04 mol hn hp A (FeO v Fe2O3) + CO 4,784 gam hn hp B + CO2 CO2 + Ba(OH)2 d BaCO3 + H2O n CO2 = n BaCO3 = 0,046 mol v n CO ( p.ư ) = n CO2 = 0,046 mol p dng nh lut bo ton khi lng ta cú: mA + mCO = mB + mCO2 mA = 4,784 + 0,046ì44 0,046ì28 = 5,52 gam t nFeO = x mol, n Fe2O3 = y mol trong hn hp B ta cú: x + y = 0,04... Cho 5,76 gam axit hu c X n chc, mch h tỏc dng ht vi CaCO3 thu c 7,28 gam mui ca axit hu c Cụng thc cu to thu gn ca X l A CH2=CHCOOH B CH3COOH C HCC-COOH D CH3CH2COOH Cõu 47: Cho 0,1 mol axit hu c X tỏc dng vi 11,5 gam hn hp Na v K thu c 21,7 gam cht rn v thy thoỏt ra 2,24 lớt khớ H2 (ktc) Cụng thc cu to ca X l A (COOH)2 B CH3COOH C CH2(COOH)2 D CH2=CHCOOH Cõu 48: Cho 3,6 gam axit cacboxylic no, n chc... thu c 13,95 gam mui khan Cụng thc cu to thu gn ca X l A H2NCH2COOH B H2NCH2CH2COOH C CH3CH2CH(NH2)COOH D CH3CH(NH2)COOH Cõu 53: X l mt -amino axit ch cha mt nhúm NH2 v mt nhúm COOH Cho 14,5 gam X tỏc dng vi dung dch HCl d, thu c 18,15 gam mui clorua ca X CTCT ca X cú th l A CH3CH(NH2)COOH B H2NCH2CH2COOH C CH3CH2CH(NH2)COOH D CH3(CH2)4CH(NH2)COOH Cõu 54: Cho hn hp X gm hai cht hu c cú cựng cụng thc phõn... axit v ru mt ln ru tỏc dng hon ton vi NaOH thu c 6,4 gam ru v mt lng mi cú khi lng nhiu hn lng este l 13,56% (so vi lng este) Xỏc nh cụng thc cu to ca este A CH3COO CH3 B CH3OCOCOOCH3 C CH3COOCOOCH3 D CH3COOCH2COOCH3 Hng dn gii R(COOR)2 + 2NaOH R(COONa)2 + 2ROH 0,1 0,2 0,1 0,2 mol 6,4 M R OH = = 32 Ru CH3OH 0,2 Page 24 p dng nh lut bo ton khi lng ta cú: meste + mNaOH = mmui + mru mmui meste = 0,2ì40 . <RU59 G : =5GH9 : →G D =H : G 2 3 CO CaCO 30 n n 0,3 (mol) 100 = = = 2 CO CO n n> ⇒G3#o I G ' k! $&v!0f!-./!. 2 C(X) C(Y) CO (do X) CO (do Y) n n n n 0,04 = ⇒ = = 59 -. 2 O Y + → G : < 2 H O n <RRU + ⇒ = + = ∑ 2 2 CO H O m 1,76