C. b anot xayra sir oxi hoa: Cu > C u^^+2e
1. Phanu-ng dien phan dung djch CuCU (vdi dien cue trcr) va phan umg an m6n dien hoa xay ra khi nhung hgp kim Zn Cu vao dung djch HCl c 6 dac diem la
Ạ Phan ling 6 cue am c6 sir tham gia ciia kim loai hoac ion kim loaị B. Phan ling xay ra luon kem theo sir phat sinh d6ng dien.
C. Deu sinh ra Cu b cue am. , . ^ , . „
D. Phan ling a circ duomg deu la sir oxi hoa CI". , „}, , „ .
Huong dan gidi
* Qua trinh dien phan (tieu ton dien nang) dung djch CuCU (dien cue tra):
Cue (-): Cu^^ + 2e > Cu (khu) Cuc(+): 2 C r- 2 e >Cl2 (oxi hoa)
* Pin dien hoa (phat sinh dong dien) Z n - Cu/ H C l : C i r c ( - ) : Z n - 2 e >Zn^"'
C i r c ( + ) : 2H^+2e A
=> Phan úng of circ am c6 sir tham gia ciJa k i m loai hoac ion k i m loaị
})ap an dung la A .
2. Phan irng hoa hoc d i l n ra trong pin dien hoa va trong binh dien phan c6 diem chiing la
A . phan ufng o x i hoa - khir xiiy ra o c a c dien circ. B. chuyen nang lirong hoii hoc thanh dien nang. C. cac phan ung d6u tir xay rạ
D. xay ra a cac dien cue nho dong dien m6t chieụ
Huong dan gidi
Phan ling hoa hoc didn ra trong pin dien hoa va trong binh dien phftn eo diem chung la phan umg oxi hoa - khijr xay ra 6 cac dien cuẹ
Y)ap an dung la A .
3. Cho bon h6n hop, m6i h6n hop gom hai chat rdn c6 s6' mol bang nhau: NâO va A 1 , 0 , ; Cu va FeCl,; BaCU va C U S O 4 ; Ba va N a H C O j . So h6n hop eo thé tan A 1 , 0 , ; Cu va FeCl,; BaCU va C U S O 4 ; Ba va N a H C O j . So h6n hop eo thé tan hoan toan trong nude (dir) chi tao ra dung dich la
A . 4. B. 2. C. 1. D . 3.
Huong đn gidi
H6n hop NâO (x mol) va A K O , (x m o l ) : N a , 0 + H . O > 2NaOH
X 2x ( m o l )
2 N a O H + A l A + 3 H . O > 2 N a | A l ( O H)4]
2x x tan > Suy ra, h6n hop nay tac dung vira du, tao ra dung dich.
- H6n hop Cu (x mol) va FeCl, (x mol):
Cu + 2FeCl, > 2FeCK + CuCl,
• :vh coiị x/ 2 X
Suy ra, Cu con d u (khong tan).
- H 6 n hop BaCl, (x m o l ) va C U S O 4 (x m o l ) :
BaCU + C U S O 4 > BaS04i + CuCU Tao ra ket tua BaS04.
- H 6 n hop Ba (x m o l ) va N a H C O , (x mol): Ba + 2H3O > BăOH), + H . X X B a ( O H ) , + NaHCỌ, > BaCO, i + N a O H + H , 0 X v' X 7 0 . : ^ ^ - -
Tao ra ket tua BaCO,.
Vay chi CO 1 h6n hop (NâO/ AKO,) hoa tan trong nude tao ra dung djch.
D a p an diing la C . Ciii dung m6t thuoc thu phan biet cac kim loai sau: M g , Zn, Fe, Bả
Ạ Dung dich NaOH ; B. Dung dich H,S04 loang "> C. Dung dich H C l D. Nude M . :
Huong đn gidi
Chon thu6'c thir la dung djch H 2 S O 4 loang thi each nhAn biet don gian nhát: - Trich cac mau thu
- Cho dung djch H 2 S O 4 vao cae mSu thu
+ MSu tao ra ket tua la Ba:
Ba + H 2 S O 4 - > BaS04 i f H j T Ba + 2 H , 0 - > B a ( O H ) ^ + H2 t
(Loc tach ket tua duge dung dich B a ( 0 H) 2 )
+ Cac m3u con lai khong tao ra k6't tiia (duge cac dung dich muoi sunfat) M g + H 2 S O 4 ^ M g S 0 4 + H2
Zn + H 2 S O 4 ZnS04 + H j Fe + H 2 S 0 4 - > F e S 0 4+ H 2
- Cho tir tir dung djch BăOH)2 tdi d u vao cac dung djch muoi thu duge:
+ MSu tao ra k6't tua, sau do tan, bdt m6t phan => MSu ban đu chua Z n
B a ( O H)2 + Z n S 0 4 - > BaS04 i + Z n ( 0 H ) 2 i
B a ( O H)2 + Z n ( O H) 2 - > B a
+ M 3 u tao ra ket tua trSng xen Ian trdng xanh => MSu ban dau chiia Fe: j
B a ( O H)2 + FeS04 ^ F e ( 0 H ) 2 i + BaS04 i Trdng xanh trdng
+ MSu c h i tao ra k6t tiia trdng => mdu ban dau ehua M g . B a ( O H ) ^ + M g S 0 4 ^ BaS04 i + M g ( 0 H) 2 i
trdng trdng
J)ap an dung la B .
Chíi v; Co the dung thude thu la nuoe:
Ba + 2 H 2 0 - ^ B a ( O H ) , ( t a n ) + H2 t :
Zn + B a ( O H ) , ^ B a Z n 0 2 ( t a n ) + H2 t ' u . ;
M g + H 2 0 ( h ) — ! — > M g O ( t r d n g )+ H 2 Q . O . M ' C-' •
n 1
3Fe + 4 H 2 0( h ) — ^ F e 3 0 4 ( d e n ) +4H2