- VI, Fe co nd => AgN03,Cu(N03)2 phai phan ling hét Dodo dung dic hX chua A1(N03)3 va Fe(N03)
6, Hoatan hoan toan h6n hop 3 kim loai Na, Zn vaFe trong dung dich H2SO
loang, thu duoc V lit khi H , (o dktc). Hoa tan hoan toan h6n hop Fe va kim loai
M ( M CO hoa tri II) trong dung djch HCl, cung thu diroc V lit khf H2 (c* dktc). Kim loai M la (biet khoi lirgng Fe trong hai h6n hop la nhu nhau, kh6'i lirong M bang m6t nira kh6'i luong Na va Zn)
Ạ Cạ B.Bạ C. Nị D. M g .
Hu&ng đn gidi
* Na, Zn, Fe tac dung vdi H 2 S O 4 loang:
2Na + H 2 S O 4 ^ Na2S04 + H 2 X x/2 (mol) Zn + H 2 S O 4 ^ 2nS04 + H 2 y y (mol) \ Fe + H 2 S O 4 ^ FeS04 + Hj z z(mol)
* M , Fe tac dung vdi H Q : j ;
M + 2HC1
t
MCI2 + H2
t (mol)
z z (mol)
Theo bai la, ta c6: t+ z = ^ + y + z=> t = ^ + y i Xi ( i )
Mat khac: M.t = ^.(23x + 65y) => 2M.t = 23x + 65y (2)
Tiir(l,2): 2M ^x ^ = 23x + 65y=>xM + 2My = 23x + 65y
=> X (23 - M) = 2y(M - 32,5) => — = Mz2^ 2y 2 3 - M V i x , y > 0 = > x / 2 y > 0 = > 2 3 < M < 32,5 => M = 24 (Mg, kim loai hoa trj II).
Dap an dung la D.
7. Cho hon hop bdt Al, Fe vao dung djch chiia Cu(N03)2 va AgN03. Sau khi cac phan ling xay ra hoan toan, thu duoc h6n hop rSn g6m ba kim loai la
Ạ Al, Fe, Cụ B. Al, Cu, Ag. C. Al, Fe, Ag. D. Fe, Cu, Ag.
Hu&ng đn gidi
Thu duoc cac kim loai Ag, Cu (tao ra) va Fe (du).
Dap an diing la D.
Dang 10; Bai tap ve h6n hop s^t va hop chat cua sit
1. Cho 11,36 gam h6n hop gdm Fe, FeO, Fe203 va Fe304 phan ling het vdi dung djch H N O 3 loang (du), thu duoc 1,344 lit khi NO (san ph^m kh-r duy nhát, 6 djch H N O 3 loang (du), thu duoc 1,344 lit khi NO (san ph^m kh-r duy nhát, 6
dktc) va dung djch X. C6 can dung djch X thu duoc m gam mu6'i khan. Gia tri I ciia m la
Ạ 38,72. B. 49,09. C. 35,50. D. 34,36.
Hu&ng đn gidi
Theo bai la: nNo = 0,06 mol
Theo nguyen tSc bao toan electron trong phan ling oxi hoa - khir, ta c6:
3m 11,36-m + 0,18
56 8
3m = 7.( 11,36 - m) + 0,18.56 => 10m = 89,6 => m = 8,96 (gam)
=^nFe = n F e ( N 0 3 ) 3 =0,16 (mol)
m =0,16. 242 = 38,72 (gam).
Ph^n loal vc)phtran^phap ^!JI nhanh Bl Hoc, Iwc iz-L,ui lumn i our,