- H6n hop X phan ling v6i Br2:
Goi Xla s6'mol m6i kim loai c6 trong mgam h6n hop X Tac6: (1)
0,015.64.100% „„ %nic„ = ~ = 78,05%.
Dung dich Y g6m AKNO,), va CuCNO,)^. Sue khi NH, (du) vao, xay ra cac phan iJng : ra cac phan iJng :
Al(NO,)., + 3NH3 + 3H2O -> AKOH),! + 3NH4NO3 (3)
Cu(N03)2 + 6NH, + 2H2O [Cu(NH3)4](OH)2 + 2NH4NO, (4) S6' mol AUOH),! = s6' mol Al = 0,01 mol. S6' mol AUOH),! = s6' mol Al = 0,01 mol.
^ m = 0,01.78 = 0,78 (gam). 27.21. Dap an diing la B. 27.21. Dap an diing la B.
Phucfng trinh phan ling :
HNO3 + 3HC1 + A u A u C l , + NO + 2H2O (1)
Theo(l): nHc, = Sn^u = 3.0,02 = 0,06 (mol).
H N O = " A U = 0.02 mol. 27.22. Dap an diing la Ạ
Phuong trinh phan ling:
2Cu(N03)2 — ^ 2CuO + 4NO2 + O2 (1)
4NO2 + O2 + 2H2O -> 4HNO3 (2)
Theo (1): 1 mol Cu(N03)2 tao ra 1 mol CuO, khd'i luong giam 108 gam. xmol- - - ymol - - - 1,62 gam. xmol- - - ymol - - - 1,62 gam. - ^ x = y= — =0,015 (mol). 108
Theo (1) va (2): S6 mol HNO3 = 2 s6' mol CuO = 2.0,015 = 0,03 mol
va 0,03 mol HNO3 hoa tan trong 0,3 lit dung dich. Vay ndng d6 mol cua dung dich HNO3 la: Vay ndng d6 mol cua dung dich HNO3 la:
CM(HN03) = 0,1 mol// = 10' mol//.
0,3 - > p H = l . - > p H = l .
27.23. Dap an dung la Ạ Phuong trinh phan ling: Phuong trinh phan ling:
CuO + CO — C u + COjt (1)
(AI2O3 + CO — ^ phan ling kh6ng xay ra) (2)
Theo (1): Khi 1 mol CuO chuy^n th^nh Cu, kh6'i luong giam 16 gam. - 0,8 gam. - 0,8 gam. Khi x mol CuO
0,8 Cu,
-> X = 16 = 0,05 mol Khd'i lucmg CuO trong h6n hop la: Khd'i lucmg CuO trong h6n hop la:
m = 0,05.80 = 4,0 (gam). 7.24. Dap an diing la B. 7.24. Dap an diing la B.
Phuang trinh phan ling:
2Cu + 4HC1 + 0 2 ^ 2CUCI2 + 2H2O
27.25. Dap an diing la Ạ Phuong trinh phan ling: Phuong trinh phan ling:
2PbS + 30, I" ^ 2PbO + 2S0,t
Goi a 1^ kh6'i luong PbS kh6ng bi d6't chdỵ Ta c6:
mol PbS bi d6t chay, tao ra
(1) 239 239
-> Khd'i luong h6n hop ran la: m - a m - a 239 mol PbO 239 .223 + a = 0,95m 16a = 4,05m a ^ 4,05 m~ 16 hay .100% = ^^""^'"^ .100% = 74,69%. m 16 27.26. Dap an diing la Ạ
Cac phuang trinh phan ling ciia h6n hop X v6i HCl:
Zn + 2HC1 ^ ZnCl2 + Hjt Cr + 2HC1 ^ CrCl2 + H2t
Sn + 2HC1 ^ SnCl2 + Hjt
Goi X la s6' mol m6i kim loai c6 trong m gam h6n hop X. Ta c6: (1) (1) (2) (3) mZnCl2 + ™CiCl2 + ^ SnCl. = 8,98 (65 + 71)x + (52 + 71)x + (119 + 71)x = 8,98 X = 0,02 = nz„ = ns„ = n^.