m o n g , ban bao ve ( k h i n h o m tao h 6 n h o n g vori t h u y ngan, t i n h l i e n tuc ciia l o p o x i t bj pha v6r, n h o m tac d u n g m a n h vori o x i ) .
1. T a c d u n g v o l p h i k i m
2A1 + 3C1, > 2AICI3
4Al,b<,„ + 3 0 , — ^ 2A1,03
2A1 + 3S — ^ AI2S3
2, T a c d u n g V(Vi axit
* D u n g d j c h axit H C l , H2SO4 loang:
2A1 + 6 H ^ > + 3H^
* D u n g d i c h H 2 S O 4 dac, n o n g :
2A1 + H 2 S O 4 — ^ A1,(S04)3 + S O 2 T + 6 H 2 O
Chii v: N h o m b i t h u d o n g hod t r o n g H2SO4 dac, n g u 6 i . * D u n g d i c h HNO3:
A l + HNO,,„„j„g,„,,,,,,,„„g, > A K N O j ) , + N,Oy + H , 0
A l + HNỌ, (1) > A K N O , ) , + N H 4 N O . , + H 2 O
San pham t a o t h a n h c 6 the c 6 m o t h 6 n h o p san p h a m khir, k h i d o l i n g v 6 i m 6 i san phitm k h i i , ta viet m o t p h u o n g t r i n h hoa h o c .
T h i d i i , n h o m tac d u n g vori axit n i t r i c t h u duoc h 6 n h o p san p h d m k h i r chiia N 2 O
va N O , t h i ta Viet t h a n h hai P T H H n h u sau:
8A1 + 3 0 H N O . , > S A K N O j ) , + 3 N 2 O T + I S H ^ O
A l + 4 H N O , > A1(N0.,)3 + N O t + 2H2O
Chu y: K i m loai A l k h o n g tan trong HNO3 dac, nguoi ( d o hien tucmg t h u dong hoa).
3 - T a c d u n g v(ii H2O
2 A 1 + 6 H , 0 > 2 A 1 ( 0 H ) , i + 3H2 '
Phan ling nay chi xay ra a be mat ciia k i m loiii nhom d o A K O H ) , tao ra bdm chac, bao v^ k i m loai nhom ben trong. Thuc te coi nhom khong tac dung vdi H j O !
Phdn loai va pluMtii^ plni/} i^iili iilia/i/i BT H6a hoc 12 - Cu Thanh Toan 4. Tac dung \(n dung dich kiem
2A1 + 2NaOH + 6 H , 0 > 2Na[Al(OH)4] + 3 H . t 2A1 + CaCOH), + 6H2O > Ca[Al(OH)4]2 + SH,
Chu y; A l k h o n g tan trong dung dich N H 4 O H (dung djch NH3, ki^m yeu). 5. Tac dung v('ri oxit k i m loai (phan umg nhiet nhom)
2A1 + Fe,0., 2Fe + AUO,
2A1 + Cr^O, 2Cr + AKOj
PTTQ: 2yAI„, + 3 M , 0 , „ — ^ 3xM,„ + yAKO,,,,
* Trong phan ting nhiet nh6m, cac chat tru6c va sau phan lifng dtu la cac chat
rSn (cac k i m loai va oxit kim loai). Do do:
' ^ c h i l rdn Irudc p/u ~ ' ^ c h a ' l r i n sau p/u
Mot so chu v;
- Cho san phdm cua phan ling nhiet nhom, tac dung vofi dung djch kiem ma c6 khi H i bay ra => trong san phaim c6 A l :
2A1 + 2NaOH + 6H.O > 2Na[Al(OH)4] + SH^T
=> A l d u hoac phan urng xay ra c6 H % <100%.
- K h i chia chat rdn sau phan ting nhiet nh6m thanh hai phdn khac nhau thi + Phdn I : dat s6' mol cac chat A, B, C, D Ian luot la x, y, z, t.
+ Phdn I I : dat dn s6' mol cac chat A, B, C, D Idn luot la kx, ky, kz, kt.