- Hoatan het phd n2 bang dung dich HNO3 dac, nong (du) tháy c6 11,76 lit khi bay ra (dktc).
3. Qi iam gam Al thanh hai phSn bang nhau:
- Phdn m6t tac dung vdi lirong du dung djch NaOH, sinh ra x mol khf H,;
- Phin hai tac dung vdi luong du dung djch HNO3 loang, sinh ra y mol khf N2O (san phdm khir duy nhát).
Quan he giCa x va y la
Ạ x = ỵ » . B. y = 2x. C. x = 2ỵ D. x = 4ỵ , J Hu&ng đn gidi
So d6 cac qua trinh:
2H^ + 2e > H , 2x < X (mol)
+5 +1 2 N +8e > 2 N 2 N +8e > 2 N
8y < y (mol)
Theo nguydn tac bao toan electron, ta c6: 2x = 8y => x = 4ỵ
Dap an diing la D-
108
Cty TNHH MTV DVVH Khang Viit
4 H^n '^^'P ^ ?>^^ Na, A l va Fe (v6i ti 16 s6' mol giCra Na va A l tuomg irng la 2 : 1). Cho X tac dung vdi HjO (du) thu duoc chat rdn Y va V lit khị Cho toan bo Y tac dung voi dung dich H2SO4 loang (du) thu duac 0,25V lit khị Biét cac khi do
it cung di^u ki6n, cac phan ung d^u xay ra hoan toan. Ti \t s6 mol ciia Fe va A l trong X tuang Ung la
Ạ 5 : 16. B. 1:2. C. 1 6:5. D. 5 : 8.
Hu&ng đn gidi
* Gpi s6' mol Na, A l va Fe trong X Idn luot la 2x, x va ỵ Na + H2O NaOH + 0,5H2 t
2x ^ 2x -> X
A l + NaOH + 3H2O NaAl(OH)4 + l.SHj t
X - > X -> l,5x
= > X + l,5x = 2,5x = V ^ X = V / 2 , 5 Chat ran Y la y mol Fẹ
* Y + H2SO4 (loang, du)
Fe + H2SO4 (^) ^ FeS04 + H2 t y -> y =>y = 0,25V
Vay np^:nA, = y :x = 0,25V: V / 2, 5 - 5: 8
Dap an dung la D. 5. Chia h6n hcrp X gom K, A l va Fe thanh hai phdn bang nhaụ
- Cho phdn 1 vao dung dich KOH (du) thu duoc 0,784 lit khf H , (dktc).
- Cho phdn 2 vao m6t luong du H^O, thu duoc 0,448 1ft khf H , (dktc) va m gam h6n hop kim loai Ỵ Hoa tan hoan toan Y vao dung dich HCl (du) thu duoc 0,56 1ft khf H , (dktc).
Khoi luong (tinh theo gam) ciia K, A l , Fe trong m6i phdn h6n hop X Idn luot la Ạ 0,39; 0,54; 1,40. B. 0,78; 0,54; 1,12. C. 0,39; 0,54; 0,56. D. 0,78; 1,08; 0,56. Hu&ng đn gidi * Phdn 1: nH2 =0,784/22,4 = 0,035(mol) „ , K + H 2 0- > . K O H + - H 2 t 0,5x 3 A l + K O H + 3 H 2 O ^ K A l (0H)_^ + ^ H2 y -> 1.5y =>0,5x + l,5y = 0,035 ( l )
Flia/i loai va />/iir(fiiy i^lúip iíúii nluiiili BT Hoa hoc 12 — Ci4 Thanh Tochi
* Phdn2: =0,448/22,4 = 0,02(mol)
"H2{P2) ' ^ " H 2 ( P | ) ' ^ ' ^ ' du (Fe khong xay ra phan ling) K + H , 0 - > K 0 H + - H 2 t 2 ^ X - > X -> (),5x A l + K O H + 3H2O ^ K A l ( O H ) ^ ^ f " 2 ^ X < - X l,5x => 0,5x + l,5x = 0,02 ^ 2x = 0,02 => x = 0,01 (2) T i r ( l , 2 ) x = 0 , 0 1 ; y = 0,02
* Y + HCI (du): =0,56/22,4 = 0,025(mol)
S 6 ' m o l A l p h a n i r n g v 6 i a x i t H C l : 0 , 0 2 - x = 0 , 0 2 - 0 , 0 1 =0,01 (mol) 3 ' A1 + 3 H C 1 ^ A 1 C 1 3+ - H 2 t 0,01 -> 0,015(mol) Fe + 2 H C l^ F e C l 2 + H2 t 0,01 <r- (0,025-0,015) Vay: =0,01.39 = 0,39(g) niAi =0,02.27 = 0,54(g) =0,01.56 = 0,56(g) Dap an diing la C.
6. Tr6n m gam Ba va 8,1 gam bot k i m loai A ! , roi cho vao luong H^O (du), sau phan ling hoan loan c6 2,7 gam chat rSn khong tan. K h i tron 2m gam Ba va 8,1 phan ling hoan loan c6 2,7 gam chat rSn khong tan. K h i tron 2m gam Ba va 8,1 gam A l roi cho vao HiO (du), sau phan ling hoan toan thu duoc V lit khi H;
(dktc). Gia trj cua V la
Ạ 11,20 B. 14,56 C. 17,92 D. 15,68
Huong dan gidi
Chát ran khong tan la A l => Khoi luong A l phan ling la 8,1 - 2,7 = 5,4(g) = > S 6 m o l A l p h a n i i n g l a 5,4/27 = 0,2(mol).
A l ( O H ) ^
Ba + 2Al + 8 H 2 0 - ^ B a /. + 4 H 2 / 4 J 2 2 0 , l < - 0 , 2 ( m o l )
\6i m (g) Ba c6 0,1 mol Ba => vdi 2m (g) Ba c6 0,2 mol Bạ
Cry TNHH MTV DVVH Khan^ Viet
Ba + 2H2O BăOH)2 + t 0,2 0,2 ^ 0,2(mol) 2AI + B a ( O H) 2+ 6 H 2 0 - ^ B a [ A l ( O H) ^ ] ^ + 3 H 2 t ; . 8 , 1 / 2 7 ^ 0 , 1 5 < 0 , 2 ^ 0,45(mol) -: £ V - Vay V = (0,2 + 0,45).22,4 = 14,56(^) Dap an dung la B.
7. Cho m gam h6n hop X gom Ba va A l (trong do A l chiem 37,156% ve khoi luong) tac dung vdi H . O d u thu dugc V lit khi H . (or dktc). Mat khac, neu