6.23. Dap an diing la Ạ
6.24. Dap an diing la B.
6.25. Dap an diing la Ạ
20f,
•
Dung N a 2 C 0 3 se loai dugc ion Câ"^ va Mg^"^ ra khoi nu6c, lam
nu6c mat tính cdng.
6.26. Dap an diing la B.
Loai ducfc nu6c ciing tam th5i nhcf cac phan ling :
CăHC03 )2 + Că0H)2 2 CaCOg i + 2 H j O » -
Mg(HC03)2 + Că0H)2 ^ CaC03>l + MgCOg + 2H2O
6.27. Dap an diing la C. c;
Loai duoc nude ciing vTnh cuu la nh6 cac phan ling : n !
CaCh + Na2C03 -> CaC03-i + 2NaCl
MgCl2 + Na2C03 ^ M g C O j i + 2NaCl
6.28 Dap an diing la D.
6.29. Dap an sai la B.
Phen chua khOng c6 kha nang diet triing.
6.30. Dap an diing la Ạ
Dung dich N a O H dac hoa tan diroc AI2O3 va Si02 :
AI2O3 + 2NaOH ^ 2 NaAlOz + H2O
SiOj + 2NaOH ^ Na2Si03 + H j O
Fe203 khong tan, dugc loai rạ Dung dich chiia NaA102 va Na2Si03. Sue k h i CO2 vao thu dugc Al(OH)3 4'.
NaA102 + CO2 + H2O -> Al(OH)3>l' + NaHCOj
Loc láy A1(0H)3, nung a nhiet d6 cao, thu dugc AI2O3 .
6.31. Dap an diing la C.
6.32. Dap an diing la D.
Criolit trgn iSn v6i AI2O3 thanh hOn hgp c6 nhiet do nong chay tháp hon ciia AI2O3 nhieu, cho phep dien phan 6 nhiet d6 tháp, tiét kiem nang lugng.
6.33. Cong thiic diing la B.
6.34. Dap an diing la Ạ
Luc diu xay ra phan ling :
NaAlOj + HCl + H2O -> Al(OH)3 i + NaCi
Sau do, do dir HCl, xay ra phan iJng trung hoa lam tan A1(0H)3 i
Al(OH)3 + 3HCl(du) ^ AICI3 + 3 HjO
6.35. Dap an dung la C.
Luc dSu xay ra phan itng :
A I C I 3 + 3NaOH ^ A l ( 0 H ) 3 i + 3NaCl
Sau do, do du NaOH, xay ra phan ling lam tan Al(OH)3>l': Al(OH)3 + NaOH(du) NaA102 + 2 HjO
6.36. Dap an diing la B.
Luc diu xay ra phan ling :
AI2(804)3 + 6 N H 3 + 6 H 2 O ^ 2 A l ( O H ) 3 i + 3(NH4)2SO A l ( O H)3kh6ng bi tan trong dung dich NH3 dụ
6.37. Dap an diing la D.
Sue khi CO2 vao dung dich NaA102 , xay ra phan ting : NaA102 + CO2 + 2 H 2 O A l ( 0 H ) 3 i + NaHCOj
6.38. Dap an dung la Ạ 6.39. Dap an dung la D. 6.39. Dap an dung la D. 6.40. Dap an diing la C. 6.41. Dap an dung la B. 6.42. Dap an diing la B. 6.43. Sutuongutig: I - D ; 2 - A ; 3 - B ; 4- C . 208 6.44. 6.45. 6.46. 6.47. 6.48. 6.49. 6.50. 6.51. 6.52. 6.53. Dap an diing la Ạ Dap an diing la C. Dap an diing la B. Dap an diing la B. Dap an diing la C. Dap an diing la D. Dap an diing la D. Dap an diing la D. Dap an diing la Ạ Dap an diing la B.
Phuong trinh phan ling ciia h6n hcrp X vori H2O : 2X + 2 H2O ^ 2 X 0 H + H2 T Theo (1) : n x = 2 n H , = 2,24 22,4 .2 = 0,2 mol. f M A = 2 3 ^ Nạ M x = — = 31 -)• 0,2 M B =39 ^ K . 6.54. Dap so dung la Ạ
Cac phuong trinh ion rut gon :
Mg2+ + COJ- -> MgCOg i
.Câ^ + C03~ -> CaC03>l'
1 j
Bâ^ + COl~ BaC03 i
(1)
(1) (2) (2) (3) Goi X, y va z la s6' mol cua Mg^"^, Câ"^ va Bâ"^ trong dung dich Dung dich trung hoa di6n ntn :
Theo(l,2, 3): 11^.^2- = x + y + z = 0,1-5 = riK^cG, • VđK3C03 = Y =0,1 lit = 100 ml.
6.55. Dap an diing la Ạ
Chu6i bién h6a do la :
Al ^ AICI3 ^ A1(0H)3 —!—^ AI2O3