Fe + CUSO4 MgS04 + C u i FeS04 i + Cu4. (1) (2)
Khi X < z < X + y, phan ling (1) xay ra hoan toan (Mg tan het), phan ling (2) kh6ng hoan toan (Fe chua tan het). Thu duoc hai kirn loai la Fe va Cụ
5.30. Dap an diing la B. Phuang trinh phan Ung : Phuang trinh phan Ung :
2AI + 3 C U S O 4 ^ AI2 ( 8 0 4 ) 3 + 3 C u i
So mol A l da phan ling = - .so mol CUSO4 = | .0,3 .0,1 = 0,02 mol.
0 *-'
Cii 2 mol A l phan ting khoi luong thanh A l tang : 3.64 - 2.27 = 138 gam. -> 0,02 mol A l phan ting khdi thanh A l tara • 1,38 gam.
^ x = 50+ 1,38 = 51,38 gam. 5.31. Dap an diing la C. X + nHCl ^ XCL + ^ Ho t (1) T h e o ( l ) : X n . 1,344 2 • Theo(2): 3,9 2 22,4 Y20n, + 2mHCl -» 2YCln, + m H j O T 2Y + 16m 2m 3,2 0,06.2 (Chu y : 0,06 . 2 Ik s6 mol HCl = 2. n^^). 5.32. Dap an diing la C. / 5.33. Dap an diing la C. FêOy+yCO — ^ xFe + y C O z t Fe + 2HC1 F e C l 2 + H 2 T 56x + 16y x X X = 32,5n. Vay n = 2, X = 65 (Zn). (2) Y = 18,67m. vay m = 3 , Y = 56 (Fe). (1) (2) Theo (1,2) : 8,12 HH, 0,105 5.34. 5.35. 5.36. 5.37. 5.38. 5.39. 5.40. 5.41. 5.42. 5.43. l,68x = 2,24y - = 1 y 4 Fe3U4 . .O Dap an diing la D. MjOx + X H 2 S O 4 ^ M2(S04)x+ X H 2 O (1)
1 mol X.98 gam 1 mol
98 100 X
Khdi luang dung dich axit = — ' = 980.x gam.
Nong d6 % dung dich mudi sunfat: C% = 12,9% = (2M + 96x).100 2M + 16x + 980x -> M = I8,66x va nghiem duy nhat: x = 3, M =56 (Fe).
Cong thiic cua oxit la Fe203 . Dap sd diing la C.
Cac phuang trinh phan iitig :
R + nHCl XCL (1)
3R + 4m H N O 3 ^ 3 R(N03 )n, + mNOt + 2m H 2 O (2) Ciing khdi luong p, tiic la ciing sd mol R. Gia su mdi trucmg hop hoa tan 1 Ciing khdi luong p, tiic la ciing sd mol R. Gia su mdi trucmg hop hoa tan 1 mol R va vi thé tich H2 bing the tich NO nen c6 ti le :
n m , m 3 — = — tuc la — = - . 2 3 n 2 Dap an diing la C. Dap an diing la B. Dap an diing la D. Dap an diing la B. Dap an diing la D. Dap an diing la D. Dap an diing la C. Dap an diing la D.
5.44. Dap an diing la D. 5.45. Dap an dung la Ạ 5.45. Dap an dung la Ạ 5.46. Dap an diing la B. 5.47. Dap an dung la C.
H2 chi khijr dugrc CuO, PbO va FejOs . Do vay trong h6n hap sau khi nung C O Cu, Pb, Fe vufa dugrc tao thanh va MgO, AI2O3 con lai (kh6ng bi H2 khut).
5.48. Dap an dung la B.
Mg la kim loai manh, tac dung vdri H2SO4 dac, ngupi cho khi H 2 S t .
Cu la kim loai yeu, tac dung v6i H2SO4 dac, ngupi cho khi SO2 t .
Al bi thu dpng hoa trong H2SO4 dac, ngu6i n c n kliOng cC ph^ii iag.
5.49. Menh de sai la Ạ 5.50. Dap ^n d u n g la B. 5.50. Dap ^n d u n g la B. 5.5^. Dap an d i i n g la Ạ 5.52. Dap an dung la B. 1 5.53. Dap an dung la B. 5.54. Dap an diing la C. /
Phirong trinh phan ling : /
Fe + MSO4 -> FeS04 + M (M hoa tri II) (1) Goi X la s6' mol Fe da p h a n l i n g .
Theo (1) : nMS04 = " M "Fe = ^ mol Ta C O : f(M + 96).x = 3,2 gam
Mx - 56x = 0,14 gam
Giai he phuong trinh ta dugrc : x = 0,02 M = 64 (Cu). C6ng thiic hoa hoc ciia mu6'i sunfat la CUSO4.
1 Q A • 1 !
5.56.
5.57.
D^p 5n dung la B.
Ki hifiu hai kim loai la A va B, h6a tri la n va m ; so mol la x va ỵ Phuong trinh phan ling :
2A + 2nHCl -> 2 A C I n+ n H 2 t • (i)
2B + 2mHCl ^ 2 BCln, + m H21 (2)
Theo (1) va (2) : nH, = . H n3 = , i l ^ . ^ ^ 0,1. n H C l = "ci- '^Hj = n x + m.y = 2.0,l = 0,2.
Ap dung dinh luat bao loan khoi lupng ta c6 :
mmutfi = mKl + " I Q - = 10 + 0,2.35,5 = 17,1.
Dap an diing la Ạ Phuong trinh phan ling :
Zn + FeS04 ^ ZnS04 + Fe
X mol X mol
Vi Zn tan ra, Fe taọthanh-lai bam vao thanh kem. Do do, kh6'i lupng thanh kem giam :
65x - 56x = 13-12,55 -> x = 0,05 mol.
vay kh6'i lupng Zn phan ling la : m^^ = 0,05.65 = 3,25 gam.
Dap an diing la B.
Trong dung dich : CUCI2 C u 2^ + 2 C r
H2O ( > + OH"
Catot(-) 1^ \ Anot(+)
Cu2+,H+ Cr.OH"
Cu^^ + 2 e C u 4 ' 2 C r - 2 e^ C l 2 t
Phuong trinh dien phan : CuClj '^^"'^ ) Cui + CI21 ,
Dap an diing la Ạ
Trong dung djch : CUSO4 ^ Cu^^ + SỖ
.H2O < > + O H "
Catot (-) Anot (+)
Cu2+,H+ S O ^ - . O H "
C u 2 + + 2 e ^ C u ^ 2 0 H " - 2 e ^ H 2 0 + ^ O j t
Trong dung dich con H"^ va SO4", do la axit H2SO4 .
Phucfng trinh dien phan :
CUSO4 + H2O _ ^ E ^ C u i + i O21 + H2SO4
5.59. Dap an diing la D.
Trong dung dich :
Na2S04 2 Na"" + 8 0 4 "
H2O < > H+ + 0 H ~
Catot (-) ^ A n o t ( + )
N a + , H ^ S O ^ - , O H -
2 H ^ + 2 e - ^ H 2 t 2 0 H " - 2 e ^ H 2 0 + ^ O j t
Phuong trinh dien phan : H2O -dfiđ_^ H2 t + ^ O2 t
5.60. Dap an diing la D.
Trong dung dich :
K O H ^ 2Na+ + SOJ' H2O < > + O H ~ Catot (-) ^ ^ A n o t ( + ) N a ^ . H ^ S O ^ ~ , O H - 2 H * + 2 e ^ H 2 t 2 0 H ~ - 2 e - > H 2 0 + ^ 0 2 t 198
Phuong trinh dien phSn :
' H2O - ^ P ^ H2t +I02T
I5.6Ị Dap an dung la D.
Trong dung dich : NaCl -> Na"^ + C I "
H2O < > + O H "
Catot {-j^ ^ A n o t (+)
N a + , H + C r , O H "
2 H " + 2 e ^ H j t 2 C r- 2 e ^ C l 2 t
Phuong trinh dien phan :
• k 2NaCl + 2 H2O JP£L_> 2NaOH + H21 + CI2 t
5.62. Dap an diing la D.
A l t A p dung dinh luat Faraday : m = —
n.F
f d day : A = 64 (Kh(5i luong m o l nguy6n tit Cu), I = 2 ampẹ
i t = 600 giay, n = 2 , F = 96500. 64.2.600 „ , ~* ^Cu = = 0,4 gam. 2.96500 ^ 5.63. Dap an dung la B.
Bi bao ve v6 tau bang thep, ngir5i ta g i n vao v6 tau nhftng manh kim loai
CO tinh khir manh hon Fe (dutig tru6c Fe trong day the di6n hoa).
I
Trong 4 kim loai cho a dap an chi c6 Zn tinh khu manh hofn Fẹ
5.64. Dap an diing la Ạ . 3
Be (day B) va Fe (day D v^ C) kh6ng tan trong nudrc d nhiet d6 thuomg.
5.65. Dap an diing la C. <? /IT,? 5.66. Dap an diing la Ạ 5.66. Dap an diing la Ạ
5.67. Dap an dung la B. 5.68. Dap an diing la D. 5.68. Dap an diing la D. 5.69. Dap an dung la B.
Tha tijmg m l u hcfp kim nho vao dung djch NaOH (du):
- d dau CO khi bay ra va hop kim tan hét la hgfp kim Na - K.
2Na + 2 H2O ^ 2NaOH + T 2K + 2 H 2 O 2 K 0 H + H j T
- 6 dau CO khi bay ra, hgrp kim chi tan m6t phSn la hcfp kim A l - Fẹ 2A1 + 2NaOH + 6 H j O ^ 2Na[AI(OH)4] + 3 T
Fe khong tan.
- 6 dau hcfp kim kh6ng tan la hap kim Cu - N i .
5.70. Dap an sai la C.
6 catot da xay ra qua trinh Mti"cation (Me"'^ hay H"*") hoac khir nguyen tur nguyen to lam dien cue (khi dien phan dung dich muoi cua nguyen t6' do). nguyen to lam dien cue (khi dien phan dung dich muoi cua nguyen t6' do).
5.71. Ket luan khong diing la D.
Khi dien phan dung dich H Q , cation H"*" chay ve catot va bi khu thanh H2 •
Do do lam pH cua dung dich tang (chir kh6ng phai giam)
5.72. Dap an diing la B. 5.73. Dap an dung la Ạ 5.73. Dap an dung la Ạ
A l CO tinh khu manh han Fe ntn bi an mon.