cau 5: Cha't nao sau day khbng th^ dung d^ l^m kh6 khi hidro clorua?
6: Phan umg nao sau day chiing to HQ c6 tinh khir?
A. 4HC1 + MnOj MnO. + CI2 + 2H2O
B- 2HC1 + Mg(OH )2 - > M g a 2 + 2H2O C. 2HC1 + CuO C u a 2 + H2O
2HC1 + Zn — ZnQ, + H2.
55
A t tfiudt mm gu'ii nhann m ttoa HQC, tap Z - Côi IHanh Toiin
Hudmg ddn gidi
- Phan ling 4 H a + MnOz > M n Q j + 0 2 + I H j O , nguyfin ttf O trong HC]
cho electron: 2Cl' > + 2e, nfin HCl trong phan ling n^y c6 tinh khif.
- d phan ling B va phan ihig C, s6 oxi hoa cua H va Q kh6ng thay ddi ntn HCl o hai phan ling n^y kh6ng th^ hifn ti'nh oxi hoa hay ti'nh khir. ,,
. +1 0
- O phan ling D, 2 H (HQ) + 2. le > Hj ntn H Q th^ hien tmh oxi h6a.
Dap in A.
C&u 7: Muefi an bj 15n cdc tap cMt Ik Na2S04, MgQz, Caa2 CaS04. Hay tnnh b^y phirong phap hoa hoc loai bo cac tap chat. Viet PTHH cua cac phan irng
\ky ra.
Hudng ddn gidi
- H6a tan mu6'i v^o nirdc r6i loc se loai bo duoc CaS04 it tan (nuorc loc v5n chua m6t lucmg nho CaS04).
- Cho v^o nude loc m6t luomg du dung dich BaQj:
BaQz + CaS04 - ằ BaS04 i + C a a 2
BaQj + Na2S04 BaS04 i + 2 N a a
Loc bo ke't tiia BaS04, nude loc chiia C a a 2 , MgClj, NaCl va BaQj dô- - Them v^o nu6c loc m6t luong dung djch NajCOj la'y du:
NajCOj + CaQz -> CaCOj i + 2Naa
NazCOj + MgClj -> M g C O j i + 2Naa
NajCOj + BaQj BaCOj i + 2Naa
- Loc bo ke't tiia, nude loc chi chiia NaCl NajCOj du. Cho nudrc loc tac dung v<M dung dich HCl du: NajCOj + 2HC1 ^ 2NaCl + C O j t + HjO
Dung djch con lai chiia NaQ va HCl du, c6 can dung dich thi HCl du bay hoi bet, thu duoc NaQ tinh khie^t.
C&u 8: Mud'i an khdng nhutig c6 tSm quan trong trong dcri s^ng hang ngay ciia con nguiri con la nguyen lieu de' san xua't natri hidroxit, clo, axit clohidric.
Vie't PTHH ciia cac phan umg diing de' san xuit cac cha't tren.
Hu&ng ddn gidi - San xuaft Qz, NaOH, H 2 :
2 N a a + 2H2O r ^ ^ ^ i — > H , T +2NaOH + C I , t
Hu&ng ddn gidi
'""'^"""^ > Na2S04 + 2 H C l t 2 N a a + H2S04,a,c)
Khi HCl tan rat nhi^u trong nude, vi vay phai dung H2SO4 dac va mu6i b tranj thai tinh th^ de' ban che' hidro clorua tao thanh tan trong nude.
Cau 10: Cho h6n hop A g6m Cu va Mg vao dung djch HCl du thu duoc 5,6 lit khi (dktc) kh6ng mau va m6t chat ran khdng tan B.
Dung dung dich H2SO4 dac, nong de' hoa tan hoan toan chat r l n B thu duoc 2,24 h't khi SO2 (dktc).
a) Viet PTHH ciia cac phan ling xay ra.
b) Tinh kh6'i luong h6n hop A ban ddu.
Hu&ng ddn gidi a) Cic phan umg
Mg + 2 H a - > M g Q j + H j t (1) Cha't ran kh6ng tan B la Cu.
Cu + 2H,S04 CUSO4 + SO, t + 2H,0 (2) 5,6
m ^ g ngSn
- San xuit axit clohidric:
H2 + —5—> 2Ha
C&u 9: De' di^u che' khi hidro clorua, ngudi ta cho mudi NaQ tac dung vdi axit
H2SO4 dac, nong. Viet PTHH ciia cac phan dug xay ra va giai thich vi sao phai dung mud'i tinh th^ va axit dam dac.
b) Theo (1): n^g = " H J = = ^,25 (mol); mM^ = 24.0,25 = 6 (g)
Z z , 4
2 24
Theo (2): = njoj = T T— = 0,1 (mol); nio, = 64.0,1 = 6,4 (g).
Khd'i luong h6n hop A la: m^^A = 6 + 6,4 = 12,4 (g).
C&u 11: Brom bj I3n tap cha't la clo. Di thu duoc brom cin \km each nao sau day?
A. DSn h6n hop di qua dung dich H2SO4 loang B. D i n h6n hop di qua nu6c.
C. DSn h6n hop di qua dung djch NaBr.
D. DSn h6n hop di qua dung djch Nal.
Hu&ng ddn gidi
Brom bj iSn tap chat 1^ clo, de thu duoc brom c^n dkn h6n hop di qua dung djch NaBr, toan b6 tap cha't CU se phan tag vdri NaBr :
+ 2NaBr > 2NaCl + Brj Dap an C.
C&u 12: Day axit nao sau day sip xe'p dung theo thvc tu giam din tinh axit?
A. H I > HBr > HCl > HF. B. HP > HCl > HBr > H I . C. HCl > HBr > H I > HF. D. HCl > HBr > HF > H I
Hu&ng ddn gidi
B^n kinh nguyen tir cac halogen (X) duoc sap xe'p giam d^n theo day: I >
CI > F, nen d6 dai lien ke't giSa cac nguyen tir X vdd nguyen tu H cung giam d^n theo day: H I , HBr, HCl, HF (1), nen kha nang phan l i ra ion H* ciia cac HX cung giam din theo day (1), tiic tinh axit giam din theo day (1).
Dap an dung la A.
C&u 13: Day ion nao sau day sSp xd'p diing theo thir tu giam din tinh khijr?
A. F" > C r > Br~ > r B. I " > Br" > CP > F"
c . B r> r > c r > F " D. a ~ > F - > B r - > r Hu&ng ddn gidi
Tmh oxi hoa ciia nguydn tir cang manh thi tinh khir ciia ion am ciia no cang yd'u.
Tinh oxi hoa ciia F > Q > Br > I , ndn tinh khijf ciia F > Br~ > Q " > F~
Dap an diing la B.
C&u 14: Vi sao ngucri ta c6 th^ didu ch6' Ch Brj, bang each cho h6n hop HjSO^
dac va M n 0 2 tac dung vdri mu6'i clorua, bromua, iotua nhimg kh6ng thi ap dung phuong phap nay d^ di^u ch6 F,? Bang each nao c6 the' di^u chd' dugc Fj? Viet PTHH ciia cac phan ling.
Hu&ng ddn gidi
Ngucd ta c6 th^ dilu ch^ CU, Brj, I , bang each cho h6n hop H 2 S O 4 dac va MnO, tac dung vori mu6'i clorua, bromua, iotua. Cac san ph^m trung gian 1^ HQ, HBr, HI bi h6n hop (MnOj + H2SO4) oxi hoa thanh Q j , Brj, I2.
Cac PTHH cua phan ling:
NaCl + H2SO4 — ^ NaHS04 + HCl MnOz + 4 H a — ^ MnQ, + 0 2 + 2H2O NaBr + H2SO4 — N a H S 0 4 + HBr
M n 0 2 + 4 H B r — ^ MnBr2 + Brj + 2H2O
Nal + H2SO4 — ^ NaHS04 + HI
MnO, + 4 H I — ^ Mnl, + I2 + 2H2O
K h 6 n g the' ap dung phuong phap trfen d^ di^u ch^ F2 vi h6n hop oxi h6a (MnO, + H2SO4) khdng dii manh di oxi hoa HF thanh F j .
Cach duy nha't di di^u che' F21^ difin phan h6n hop KF tan trong HF long khan
(kh6ng C O mat HjO). Dung dong didn m6t chi^u 8 - 12 v6n ; cucmg d6 4000 - 6000 ampe; binh didn phan c6 eatot lam bang thep dac biet hoac bang d6ng va anot lam bang than chi (graphit).
dcatot: 2H" + 2 e^ H 2 d anot: 2F ^ F, + 2e
Cau 15: Bang phuong phap hoa hoc nao c6 th^:
a) Xac djnh duoc c6 khi clo iSn trong khi hidro clorua?
b) Thu duoc khi clo tCr h6n hop khi b cau a?
c) Thu khi hidro clorua tiJr h6n hop khi a cau a?
Viet PTHH ciia cac phan ung xay ra.
\ ddn gidi
Cdch 1: Cho h6n hop khi di qua dung djch NaBr hoac dung dich NaT, CI, se oxi hoa NaBr hoac Nal thanh Br, hoac I , lam cho dung djch khdng mau ban diu chuyen thanh mau vang hoac mau nau.
a, + 2NaBr -> 2NaCl + Br2 (dung djch c6 mau vang) hoac + 2NaI -> 2NaCl + I2 (dung dich c6 mau vang nau)
Cdch 2: Co thi nhan bid't h6n hop khi bang gia'y quy tim ^m. Luc d^u quy tim chuye'n thanh mau do, do h6n hop khi c6 HQ. Sau d6 mau do bie'n mat do trong h6n hop CO khi Ch. Khi 0 2 tac dung vdi H2O sinh ra HCIO c6 tinh oxi hoa rat manh, lam mat mau do.
CI2 + H2O ^ HCl + HCIO
b) Cho h6n hop khi trdn (HCl va CU) tac dung vdi chat oxi hoa manh nhu MnO,, dung dich KMn04... HCl bj oxi hoa thanh CI2 kit qua thu duoc chat khi duy nha't la 0 2 .
4HC1 + Mn02 -> M n a 2 + Q , + 2H2O
16HC1 + 2KMn04 ->• 2KC1 + 2MnCl, + SCU + 8H2O
c) Cdch 1: Cho h6n hop khi trdn tac dung vdi m6t lucmg vira dii H2 khi chie'u sang, thu duoc khi duy nha't la HCl:
CI2 + H , ) 2HC1
Cdch 2: Cho h6n hop khi di qua 6'ng dung b6t d6ng kim loai d6't nong, khi tac dung v6i d6ng kim loai tao mu6'i clorua la cha't ran. Cha't khi khdng tac dung v(5ri d6ng kim loai la HCl, nen chat khi di ra chi m HCl.
Cu + a, '° > CuCli
cau 16: Co 4 lo kh6ng c6 nhan dung rieng biet cdc mu6'i: KF, K Q , KBr, K I . Hay cho bie't:
a) Cach phan biet mu6'i dung trong m6i lo bang phuong phap hoa hoc.
b) Tir nhOng mud'i da cho di^u chd' cac halogen tuong ihig \h. cac hidro halogenua tuong ling.
Hu&ng ddn gidi
a) Cdch 1: La'y m6t it cha't trong m6i lo dem hoa tan vao nu6c duoc cac dung djch ri^ng biet, sau do lin luot cho AgNOj v^o cac dung dich do se nhan ra duac cac dung djch do xua't hl6n cac hidn tuong khac nhau:
KF + AgNOj > Kh6ng phan ihig ' KCl + AgNOa > AgCl i + K N O 3 '
(niau trdng) ^ .
KBr +AgNOj > AgBr^ + K N O 3
(mau vang nhat) ,
Ki thu4t tn6i gidi nhanh BT Hod hgc, tap 2-Cu Thanh Toan
K I + A g N O j > A g l i + KNO3
(mdu vang)
Cdch 2: La'y m6t it chat trong m6i lo dem hoa tan vao nir6c diroc cac dung dich rifing biet.
- Dung djch nho tac dung duoc nir6c brom tao ra tinh th^ c6 mau den tim, do la dung dich K I .
Br2 + 2 K I ^ 2KBr + l2
- Nhutig dung dich con lai, dung djch nao tac dung duoc voi Clj tao ra dung dich C O m^u vang nau (mau ciia Btj tan trong nu6c), do la dung dich KBr.
+ 2KBr -> 2KC\ Br,
- Hai dung dich con lai la K F va KCl : Cho tac dung vdi dung dich AgNOj, dung djch nao tao ra k6t tiia trlng, do la dung dich K C l .
K Q + A g N O j ^ AgCl i + KNO3
- Dung djch con lai la K F , kh6ng phan utig vdri A g N O j . b) Dieu che halogen tUcmg iTng tiJt mud'i da cho :
- Diiu ch6 F,: D'l&n phan K F tan trong chat long H F khan thu duoc F , or an6t.
- D i l u che' Clf. Didn phan dung djch K Q trong nu6c, c6 mang ngan.
2Ka + 2H2O _ J P ^ H , t + CI21 + 2 K O H
m.n
* Di^u che Br,: Cho H2SO4 dac tac dung vdi h6n hcxp rSn KBr va M n O j dun nong:
2KBr + H2S04,<,j,) — ^ K2SO4 + 2HBr (1) M n O j + 4HBr — ^ MnBr, + Br, + 2H2O (2) MnBr, + H2SO4 — ^ MnS04 + 2HBr (3) Phan umg t6ng cua (1), (2), (3) la:
2KBr + M n O , + 2H2SO4 K.SO, + MnS04+ Br2+ 2H2O (4) - Di^u cha' I2 tuong tu di^u che Br2 va c6 phan ling t6ng la:
2 K I + M n O , + 2H2SO4 — ^ K2SO4 + MnS04+ I2+ 2H2O Dieu chehidro halogen tit cac muoi tuang itng:
- Didu cha' H F : K F + H2SO4 — ^ KHSO4 + H F T - D i l u cha' H C l : K Q + H2SO4 — ^ KHSO4 + HCl t
- Di^u cha' HBr: Dian phan dung djch KBr c6 mang ngSn (hoac tac dung vdri dung djch KBr, hoSc cho mu6'i KBr tac dung vdri h6n hop Mn02 va H2SO4 dac) duoc Br,, sau do cho Br, tac dung vdri H j 6 nhiat d6 cao diroc HBr.
2KBr + 2H2O — ^ E ^ l ^ H2 + Br, + 2 K O H H2 + Br, — ^ 2HBr
Di^u che' H I : tuong tir di^u che' HBr b Irtn hoSc tir I , ta dieu che' H I bang each dung khi H,S khu I , .
I , + H,S — ^ 2HI + S
C&a l ^ - ^ ' " ^ m\x6\l cAn thie't d^ c6 10 tain mu6'i an chiia 2,5% Nal. _ • ,
Hu&ng ddn gidi
Trong 10 tab mu6'i an chiia 2,5% Nal ^ Vh6i lugmg mu6'i N a l c6 trong 10 ta'n niu6-i an = = 0,25(ta'n)
Vay kh6'i luong ciia N a Q = 10 - 0,25 = 9,75(ta'n).
Cka 1 8 : M6t h6n hop Y g6m A l va Fe. Cho 22 gam Y tac dung vdri 2 lit dung djch H Q 0,3M thu diroc V lit khi H , (dktc). ^ a. Chung minh rang h6n hop Y kh6ng tan het. Tinh Vj^^ (dktc).
b. Cho 22 gam Y tac dung vdri clo du thu duoc mj gam mu6'i. Na'u cho 22 gam Y tac dung v6i iot du thu duoc m2 gam mu6'i. Biet m2 - m, = 139,3 gam. Tinh khd'i luong m6i k i m loai trong 22 gam Y.
Hu&ng ddn gidi
a) Dat s6' mol A l va Fe c6 trong 22g h6n horp Y la x mol v^ y mol.
A l + 3 H ^- ) > A P* + 3/2H,T (1) Fe + 2 H * ^ F e - ^ + H 2 t (2)
H H C I = 2. 0,3 = 0,6 (mol)
Gia sir kim loai phan ling hat - > nH* phan ufng = 3x + 2y
V i kim loai het nan: 3x + 2y < 0,6 ( I ) "it t Tac6: 0 ^ 4 . ,= x + y - > ^ < x + y < ^ ^ 0,392 < x + y < 0,815
56 27
0,784 < 2x + 2y < 3x + 2y (II) TiJr (I) va (II) ta tha'y di^u gia sir sai. Vay axit phan ufng hat
- > n H , = - n + = 0 , 3 mol = 0,3. 22,4 = 6 , 7 2 l i t .
^) Cac phuong trinh phan ung:
A 1 + - a , - > AICI3
2 •
F e + - C l , - > F e C l 3 , . . '
~ * m , = I 3 3 , 5 x + 162,5y (1) A l + - I , - > A l l 3
2 • Fe + I , ^ Fel 2
61
- > m 2 = 408x + 310y (2) Theo hM ra ta c6; 27x + 56y = 22
m j - m , = 139,3 ^ 2 7 4 , 5 x + 147,5y= 139,3 ' iằ \
- > X = 0,4 mol va y = 0,2 mol. ; ^ u .T,r
Vay ITIAI = 10,8 gam va m p . = 11,2 gam. i ^ • ằ ' ằ "
Cau 19: Cho h6n hop A g6m c6 NaCl, NaBr \h Nal. Hoa tan 5,76 gam A vko nu6^
r6i cho tac dung vdi lirong du dung dich nude brom, sau phan ufng hoan tokn thu ducrc 5,29 gam mu6'i khan. Mat khac, khi hoa tan 5,76 gam A vao nuoc r6i cho m6t luomg khi clo di qua, sau phan ting c6 can thu diroc 3,955 gam mu6'i khan trong d6 c6 chiia 0,05 mol NaCl.
^ 1. Viet cac PTHH ciia cac phan irng xay ra.
2. Tinh % kh6'i luong cac chat trong h6n hop A.
Hu&ng dan gidi 1. Cac PTHH xay ra:
2NaI + Br, > 2NaBr + 1 , (1) 2NaI + a, > 2NaCl + I , (2) 2NaBr + CI, > 2NaCl + Br, (3) 2. Goi a, b, c Idn luot la s6' mol ciia NaQ, NaBr, Nal, theo d^ ta c6:
58,5a + 103b + 150c = 5,76 (*) Theo (1) va theo bai ra ta c6:
58,5a + 103(b + c) = 5,29 (**) Tur (*) va (**):
r58,5a +103b + 150c = 5,76
1 i ^ =>c=0,l
[58,5a + 103(b + c) = 5,29
* Xet trufirng hofp 1:
Nal du => NaBr chua phan ting.
Goi X la s6' mol Nal phan ling. Theo ptpu (1) va (2) vk theo b^i ra ta c6:
58,5(a + X) + 103b + 150(c -- x) = 3,955 (***)
a + x = 0,05 (****) Ke't hop (*), (**), (***), (****) (loai vi c - X < 0)
* Xet t r u ^ g hflfp 2:
NaBr phan ung 1 phSn => Nal phan irng he't.
Goi y la s6' mol NaBr phan ufng. Theo (1), (2), (3) v^ theo b^i ra ta c6:
58,5(a + c + y) + 103(b - y) = 3,955 (*****)
a + c + y = 0,05 (******) Ke't hop (*), (**), (*****), (******) ta c6:
58,5a + 103b + 150c = 5,76 58,5a+ 103{b + c) = 5,29
a = 0,02 (mol)
b = 0,03(mol), y = 0,02(mol) ,
- > % m N . . = 26%, % m N, B r = 53,65%, %mN,ci = 20,35%.
C^u 20: Co h6n hop 3 mu6'i MgClj, NaBr va Nal. Hoa tan h6n hop v^o nirdc diroc dung djch X. Cho X tac dung vod 500 ml dung dich AgNO, 1,7M, thu duoc
109,1 gam ke't ttia. Loc la'y dung dich, sau do thfim m6t luong Mg kim loai (du) vao dung djch nay, khua'y ki cho dd'n khi phan ling hoan toan tha'y kh6'i luong kim loai tang 19,2 gam. Nd'u sue khi Clj dir vao dung djch X cho de'n khi cac phan utig hoan toan sau do c6 can dung djch, thu duoc 33,625 gam mu6'i khan.
Viet cac PTPU" xay ra va ti'nh thanh ph^n % kh6'i luong ciia m6i chat trong h6n hopdSu.
Hu&ng ddn gidi Theo bai ra: n^gNOj =0,5.1,7 = 0,85(mol)
Goi X, y, z \in luot la s6' mol MgQ,, NaBr va Nal trong dung djch X.
* X tac dung vol dung djch AgNOj:
MgCI, + 2AgN03-> 2Agai + MgCNOj),
X 2x ^ 2x
NaBr + AgNOj ^ AgBri + NaNOj r ,
y -> y y V?
Nal + AgNOj -> A g l i + NaNOj z -> z -> z
2AgN03 + Mg -> MgCNOj), + 2 A g i (0,85 - 2x - y - z) ^ (0,85 - 2x - y - z)/2 (0,85 - 2x - y - z)
Theo bai ra ta c6: 108 (0,85 - 2x - y - z) - 12 (0,85 - 2x - y - z) = 19,2
= > 0 , 8 5 - 2 x - y - z = 0,2z:>2x + y + z = 0,65 (1)
Mat khac ta c6: ke't tiia thu ducằc g6m 2x mol AgQ; y mol AgBr v^ z mol Agl
=>287x+ 188y + 235z= 109,1 (2)
* Khi (du) phan ihig voi dung djch X: *
a, + 2NaBr-> 2Naa + Br2 ' y -> y
CI, + 2NaI -> 2Naa + 1 ,
z -> z
a , + MgQ, -> Kh6ng xay ra ^ 5a, + Br2 + 6H2O lOHQ + 2HBr03 ô ' '
SQj +12 + 6H2O ^ 1OHCI + 2HIO3
^U6'i thu diroc g6m: (y + z) mol NaQ; x mol MgQj
=^ 58,5 (y + z) + 95x = 33,625 (3) 63
TCr (1, 2, 3) => X = 0,2; y = 0,15; z = 0,1
Vay thanh phan % kh6'i lucmg m6i chat trong h6n hop:
95.0,2.100%
% m = = 38,42%
95.0,2 + 103.0,15 + 150.0,1 p.;** ^-^^
103.0,15.100% .,^.a,
% m K, „ o , = = 31,24%
"^^^^ 95.0,2 + 103.0,15 + 150.0,1
% m N a , = 100 - (38,42 + 31,24) = 30,34%.
Cau 21: Sau khi dun nong 23,7 gam KMn04thu duoc 22,74 gam h6n hop ch&i ran.
Cho h6n hop chat ran trfin tac dung hoan toan vdi dung djch axit H Q 36,5%
(d = 1,18 g/ml) dun nong.
1) Viet PTHH cua cac phan umg xay ra.
2) Tinh th^ tfch khi CI, thu duoc (d dktc).
3) Tinh the' ti'ch dung djch axit HCl cin diing.
Hu&ng dan gidi 1. Cac phuong trinh phan ling xay ra: ,o
2 K M n 0 4 — > K2Mn04 + M n O j + O2 t
Chat ran sau phan ling g6m: K2Mn04, MnO, va KMn04 chua phan utig.
Cho san ph£m tac dung vdi dung djch HCl c6 cac phan ung:
2KMn04 + 16HCI ^ 2KC1 + 2MnCU + 5 0 , + SHjO K2Mn04 + 8HC1 ^ 2KC1 + MnCl, + 2CI2 + 4H2O
M n O j + 4HC1 —^ M n C l 2 + CI2 + 2H2O Ta CO cac qua trinh:
Mn^^ + 5e M n * ^ 0,15 mol 0,75
20'^ ->• O2 + 4e
(23,7-22,74)732 0,12
2 C r ^ CI2 + 2e -
X 2x
Ap dung djnh luat bao toan electron ta c6:
5. 0,15 = 0,03. 4 + 2x -> x = 0,315 mol - > V = 0,315. 22,4 = 7,056 lit <
Ap dung djnh luat bao toan nguyen t6:
" H C l = n K C i +2nMnci2 +2nci2 =0,15 + 2.0,15 + 2.0,315 = 1.08 mol X , 1,08.36,5.100 ^,
vay V , „ „ , , i , , H O = ^ = 91,53(ml).
64
. 22: Hoa tan hoan toan h6n hc^ X g6m Fe va M g bang m6t luong vifa du dung dich HCl 20%, thu duoc dung djch Y. N6ng do cua FeCXj trong dung djch Y la 15 76%. Tinh n6ng d6 ph^n tram cua MgCl2 trong dung djch Y.
Hu&ng ddn gidi
Goi X va y I5n luot la s6' mol cua Fe va M g trong 1 mol h6n hop Phan ling: Fe + 2 H a ^ FeQj + H^ (1)
M g + 2 H a M g Q j + H2 (2) • i. < , Theo (1, 2): n(Ha) = 2 mol va n(H2) = 1 mol
Suy ra: m (dung djch moi) = 56x + 24y - 2 + 36,5. 2. 100/20 = 56x + 24y + 363
X + y = 1
'CI
Tac6he: 127x
vay: C%Mgci2 =
^ 15,76 56x + 24y + 363~ 100
95.0,5.100
r:>x = y = 0,5
-% = 11,79%.
V
56.0,5 + 24.0,5 + 363
Cau 23: Nung 14,38 gam h6n hop KCIO3 va KMn04 in6t thori gian duoc h6n hop chat ran A va 1,344 lit (dktc) khi thoat ra. Cho dung djch HCl dac, du vao A de'n khi cac phan ung ke't thiic tha'y c6 3,36 lit khi (dktc) thoat ra (cho rang cac khi tao ra d i u thoat he't khoi dung djch). Thanh ph^n % kh6'i luong ciia KMn04 trong h6n hop ban dSu la
A. 35,6%. B. 65,9%. C. 76,8%. D. 56,8%.
Hu&ng ddn gidi ' -
Theo bai ra: =0,06 (mol); nci2 =0,15(mol). ,
Ta CO so do cac qua trinh xay ra: V KCI
Mn02 KCIO3 KMn04 , (A)
£>at x, y l^n luot la s6' mol cua KCIO3, KMn04 trong h6n hop ban ddu.
Theo bai ra ta c6: 122,5x + 158y = 14,38 (1)
Theo djnh luat bao toan electron ta c6: 6x + 5y = 0,06.4 + 0,15.2 Tfr (1, 2) ta c6: x = 0,04; y = 0,06.
Vay % „ , _ _ . 1 ^ ^ : 0 , 2 ^ . 65,9%
+.5
K C I O 3 K M n O .
- 0 2
+HC1 -CI2
K C I - I
M n C l . +2
(2)
14,38
'KMn04
^ ^ p an dung la B.
Cac qua trinh cho - nhan electron:
a*' + 6e ^ Cr' M n " ' + 5e
20- - 4e O, 2Cr' - 2e
Mn* 2
CI2.
C H U Y i N o f 2 : K T T H U A T G I A I NHANH CAC DANG BAi TAP VE N H 6 M O X I - Ll/U H U t N H
A . L I T H U Y f i T
I . T6N G Q U A N V f i C A C N G U Y £ N T 6 N H O M O X I ( N H O M V I A ) Oxi (O) Luru
huynh(S) Selen (Se) Telu (Te) Poloni (Po) Ca'u hinh
electron lop ngoai cung
3s^3p* 4s-4p'* 5s-5p'' 6s'6p'
0,066 0,104 0,117 0,137 0,164
D6 am didn 3,44 2,58 2,55 2,10 2,00
I , (kJ/mol) 1314 1000 941 869 812
Phan tit ben o. phucng) Ssda Seoo Teoo Po (tinh the kim loai M^u sic kh6ng
mau mau v^ng mau xam trlng bac trang bac D(g/cm^) 1,27.10"^ 2,06 4,80 6,24 9,30
t°„c(°C) -218,9 119,3 217 449,3 254 -182,96 444,60 684,90 990,00 962,00 Ham lucmg a
v6 trai da't (%
stf nguy6n tCr)
58,0 0,03 10' 10' 2.10"
Hop chat
voi hidro H2O K2S H2Se H2Te ^
Tinh ben giani dan
Hep chat hidroxit
H2SO4 H2Se04 H2Te04 ^ Tinh axit giam dan
I I 0 X 1 , O Z O N V A H I D R O P E O X I T
Tinh chat vat
Tinh chat hoa hoc
Oxi (O2) - K h i kh6ng mau, kh6ng miii-
- ft tan trong nir6c.
* La phi k i m hoat d6ng c6 tinh oxi hoa manh.
- Phan tur tuong doi bin (Eo = o = 494kJ/mol) O . >2000''c 0 + 0 - Tac dung vdi hSu het kim loai (trir A u , Pt) va hiu het phi kim (trur halogen):
. . . ^ 200°C
4Ag H- O . >
2 A g, 0
2Cu + O , — ^ 2CuO 2CO + O . ^ 2CO,
2H, + O , 2 H , 0
Ozon (O3) - Khi mau xanh nhat, CO mui dSc trung.
- O 3 tan gap I 6 I & O 2 .
* Co tinh oxi hoa rat manh va rnanh hon - Rat k6m b^n:
O 3 >02 + 0 - Oxi hoa Mu het cac kim loai (trijf A u , Pt) va phi k i m : 2Ag + O 3
-> Ag20 + O2
3 C u + O 3 .0
3 C u O 3 C O + O 3 - > 3CO2
3 H 2 + O 3 - > 3 H 2 0
O 3 + 2KI + H2O
^ I2 + 2KdH + O2
Hidro peoxit (H2O2) - Chat long kh6ng mau nang hon nir6c.
- Tan v6 han trong nu6c.
* Viifa CO tinh oxi hoa (manh) vufa c6 tinh k h i .
- K ^ m b ^ n : 2 H 2 0 2 XI
2 H 2 0 + 0 , -Tac dung v6i chat khu:
H2O2 + 2 K I ->
I2 + 2 K 0 H H2O2 + SO2
H2SO4 H2O2 + K N O 2
K N O 3 + H2O - Tac dung vdi chat oxi hoa:
5 H 2 0 2+ 2 K M n O , + 3H2S64 -> 2MnS04
+ 5 O 2 + K,S04 + 8 H , 0
H,o,+ a .
O, + 2HC1 Che' - Chung ca't phan doan
khong khi long.
- 6CO, + 6 H , 0
- 3 0 , uv 4. 2O3
as.xt C,HnO, + 6 0 . - Nhiet phan:
2KMn04
KMnO, + O2 + MnO.
2 K C I O 3 >
2 H, 0 ,
2KC1 + 3O2
^ O , + 2 H , 0
67
I I I . LirU H U Y N H VA H I D R O SUNFUA
Liru huynh (S) Hidro sunfua (HjS) T i n h
chflft v | t l y
- L a tinh thd' mau vang, kh6ng tan trong nirdc, tan trong dung m 6 i hiru ca.
- La chaft k h i khdng mau, m u i tning thd'i, d6c, ft tan trong nude.
T i n h chA
hoa hoc
- T i n h khir:
S + — ^ SO, 2 S + C I , — ^ s , a 2 S + S F , > SFg S + 2H2S04<^) >
3SO2+2H2O S + 6HN03(,) >
H2SO4 + 6NO2 + 2H2O - Tinh o x i hoa:
S + Fe ' ° > FeS
HgS,,)(fthuomg) S + H2 < ^ HjS
- Tinh k h u manh:
2H2S + 302(d^, _> 2SO2 +2H2O H2S(k) + a2(k, — • 2 H a + S4.
H2S + 4 0 2 + 4H2O ^ SHO + H2SO4 H2S + 3H2S04(j) > 4SO2 + 4H2O H2S + 6HN03(a)->
S O 2 + 6 N O 2 + 4H2O 2H2S + SO2 ^ 3 S + 2H2O
HjS + 2 F e a 3 ^ S + 2 F e a 2 + 2HO - Tinh axit: axit rat yfi'u, tao 2 loai mu6'i(S--,HS-):
HjS + N a O H > NaHS + H2O H2S + 2NaOH > NajS +2H2O H2S + CUSO4 > CuS i + H2SO4
Dieu che
HjS + O2 > S + H2O 2H2S + SO2 >
3S + 2H,0
FeS + 2Ha — ^ H j S t + F e O j
Nhan biet
Chat ran, mau vang, khdng tan trong nirorc
Pb(N03)2 + H2S - > P b S i + 2HNO3 den
68
L U U H U Y N H D I O X I T V A L U U H U V N H T R I O X I T
Luu huynh dioxit, SO2 Liru huynh trioxit, SO3
chA v a t l y
- L a chat k h i , khdng mau, m i i i hac, nang hem khdng k h i . - Tan nhi^u trong nudrc, k h i d6c.
- L a chat long, khdng m ^ u . - Tan v d han trong nu6c va trong axit sunfuric (tao ra oleum H2SO4. nS03).
' f i c
dung vori S 0 , , „ + H20 ^ H.SO,^,,^ SO3 + H2O >H2S04, A H< 0
T i c d u i i g ^ v6i k i ^ m
Tao ra 2 loai mu6'i:
SO2 + N a O H -> NaHSOj SO2 + 2 N a O H - > Na2S03 + H2O
Tao ra mud'i sunfat:
SO3 + 2 N a O H - >
Na2S04 + H2O
Tac dung voi oxit
baza
SO2 + CaO > CaS03 SO3 + PaO > CaS04
Tinh o x i
hoa SO, + 2 M g — ^ S + 2 M g O SO, + 2H2S > 3S + 2H2O SO2 + 4 H I - > 2I2 + S + 2 H, 0
SO3 + 2 K I > I2 + K2SO3 3 S 0 3+ 2 N H 3^ N 2 +
+ 3SO2 + 3H2O 2SO3 ' ^ ^ ^ > 2SO2 + O2 Tinh
khir 2 S O , + 0 2 < >• 2SO3, A H< 0
SO, + NO2 > SO3 + N O S02(k) + CI20,) > S020,(h) SO2 + Brj + 2H2O >
2 H B r + H2SO4 SO, + 2FeCl3 + H2O >
2FeCl2 + 2HC1 + H2SO4 5 S O , + 2 K M n 0 4 + 2H2O >
K2SO4 +2MnS04 + 2H2SO4 D i l u
- S + O2 — ^ SO2 - 4 F e S 2 + IIO2 — ^
8 S O 2 + 2Fe, 0 3 ,0
- N a, S 0 3 „ + H2S04ô,d) >
S O , t + Na,S04 + H2O
- 2 S O 2 + O2 < = = ± 2S03(h, - H2S04.nS03 — ^ XSO3
+ H2S04.(n-x)S03
6Q
V . s o S A N H A X I T S U N F U R I C L O A N G V A A X I T S U N F U R I C Axit sunfuric losing Axit sunfuric dac, n 6ng DiSn l i H2SO4 > H* + HSO4
HSO4 ^ H * + S04-
H2SO4 > IV + HSO4- (m6t pMn) H2SO4 > H2SO4 (chu ye'u) Tac
dung vdri k i m
loai
Zn + H2SO4 ZnS04 + H . t Fe + H, S 0 4 - > F e S 0 4 + H 2 t Cu + H,S04 khdng xay ra
Zn + H2SO4 ->• ZnS04 + ^
2Fe + 6H2SO4 - > Fe2(SO + : Cu + 2H2SO4 CUSO4 +
SO2
S + H 2 O H j S
4)3 +
5SO2 + 6H2O SO2 + 2H2O Tac
dung v6i phi
k i m
Kh6ng phan ling
S + 2H2SO4 - ) . 3 S 0 2 + 2H2O
2 C + 4H2SO4 - > 2CO2 + 4SO2 + 4H2O H . + H2SO4 ^ SO2 + 2H2O
Tac dung vdi oxit
baza, mu6'i CO tinh khijr
FeO + H2S04-> FeS04+ H.O Fe304+4H2S04^ FeS04 +
+ Fe2(S04)3 + 4 H 2 0 Fe(OH)2+ H2S04-> FeS04 4
+ 2H2O FeCOj + H2SO4 ^ FeS04 +
+ CO2 + H2O
2FeO + 4H2SO4 _> Fe2(S04)3 + + SO2 + 4H2O 2Fe3O4+10H2SO4 3Fe2(S04)3 +
+ S O 2 + IOH2O 2Fe(OH)2+4H2S04-> Fe2(S04)3
+ S O 2 + 6 H 2 O 2FeC03+ 4H2S04^ Fe2(S04)3
+ SO2+ 2CO2 + 4H2O Tac
dung vdi oxit
baza, baza, mu^i khdng c6 tinh
khur
F e j O j + 3H2SO4 > Fe2(S04)3 + SH.O CuO + H2SO4 > CUSO4 + H2O
2 F e( O H)3 + 3H2SO4 > Fe2{S04)3 + 6H2O 2 N a O H + H 2 S O 4 > Na2S04 + 2H2O H,S04 + Na2S03 > Na,S04 + SO, + H , 0
H 2 S O 4 + K, C 0 3 > K2SO4 + CO2 + H , 0 Tac
dung vdri hcrp cha't c6 tinh khijf
FeS + H2S04 > FeS04 + H2S
3H2SO4 + H2S - > 4SO2 + + 4H2O H2SO4 + 2 H B r ^ SO2 +
+ Brj + 2H2O H2SO4 + 8 H I - > H2S +
+12 + 4H2O
j V i U ^ I S U N F U A V A MU6l S U N F A T
Mudi sunfua ( S ' ) Mudisunfat ( S O 4 )
— f f n i v t a n - Hdu he't d^u khdng tan (trCr mudi sunfua ciia cac k i m loai nhdm l A , I I A (trCr BeS), amoni).
- HSu he't d^u tan (tril BaS04, PbS04, SrS04, CaS04).
- Khdng mau: Na.S, KjS, CaS, BaS, ...
- M a u den: CuS, PbS, Ag.S, FeS,...
- M a u trang: ZnS,... , , - M a u vang: CdS,...
- Mau do: HgS,...
- M a u hdng: MnS.
- M u d i sunfat khan hSu nhu diu c6 mhu trSng.
- C U S O 4 . 5 H 2 O (hoac dung djch C U S O 4 ) cd mhu xanh lam,....
Phan u T i g
thiiy phan
- M u d i sunfua tan trong nude, bi thuy phan manh cho m d i trudng kiem:
S- + H 2 O fz> H S + O H "
- M d t sd mudi sunfua nhu AI2S3, Fe,S3, Cr2S3, M g S bj thuy phan hoan tokn:
AI2S3 + 6H2O ^ 2 A 1 ( 0 H)3 + 3H2S
- M u d i sunfat tan ciia k i m loai trung binh hoac y€u bi thiiy phan tao ra m d i trudng axit:
C U S O 4 + 2H2O
Cu(OH)2 + H 2 S O 4
Tac dung vdri cha't oxi hoa
PbS + 4 O 3 ^ PbS04 + 4O2 CU2S + 12HNO3 — ^ C U S O 4 +
Cu(NO3)2+10NO2 + 6H2O
Khdng xay ra
Tac dung vdi axit H 2 S O 4
loang, HCl
M2S„ + 2 n H * ^ 2 M" * + n H 2 S t FeS + 2Ha FeCK + H2S Na2S +H2S04-> Na2S04+H2S
Khdng xay ra
Mu6'i khdng tan trong nw6c, trong
axit HCl, H2SO4 loang.
- M u d i sunfua cua cac k i m loai nang nhu CuS, Ag2S, PbS, HgS,...
- Cac mudi nhu BaS04, SrS04, PbS04,...
Nhan bie't - Gia'y t^m dung dich Pb(N03)2, AgNOj hoac CUSO4,...:
Pb-" + S'- > PbSi den
2Ag" + S-- > Ag2S iden Cu-* + S-- > CuS i d e n
- Dung dich chiia ion Ba'*:
Ba^* + S 0 4 " - ) • BaS04i trang
71