IV. MOT SOH OP CHAT QUAN TRONG CUAN H6M 1 N h o m oxit, AljỌ,
4. Cho 3,68 gam h6n hop gom Al vaZn tac dung vdi m6t lucnig vira du dung dich H SO4 10%, thu dugc 2,24 lit khi H , (a dktc) Kh6'i lugng dung dich thu dugc
H.SO4 10%, thu dugc 2,24 lit khi H , (a dktc). Kh6'i lugng dung dich thu dugc sau phan ihig la
Ạ I01,48gam. B. 101,68gam. C. 97,80 gam. D.88,20gam. '
Huong dan gidi
u^- 2,24 Theo bai ra: n „ . =
2 22,4 = 0,1 (mol) = 0,1 (mol) " H 2 S O 4 = rin = 0,1 (mol) m, 0,1.98.100 • <w H 0 so ^ - = 98 ( g a m ) . 10 So do phan ung: • Kim loai (Al, Zn) +H3S04(1)
Theo dinh luat bao toan khoi lugng:
n i k i m loai + Tlđ H 2 S O 4 " muAi + 2
-> m u o i + H i t
3,68 + 98 = m,,,„„« + 0 , 1 . 2 =>ni,,„„,; = 3,68+ 9 8 - 0 , 1 . 2 = 101,48 (gam).
Dap an dung la Ạ 5- Hoa tan hoan toan 12,42 gam A l bang dung dich HNO, loang (du), thu dugc
dung djch X va 1,344 lit (6 dktc) h6n hgp khi Y g6m hai khi la N , 0 va N . . Ti khoi ciia h6n hgp khi Y so vdi khi H . la 18. Co can dung djch X , thu dugc m gam chát rdn khan. Gia tri ciia m la
Ạ 97,98. B. 106,38. C. 38,34. D. 34,08.
Huong dan gidi
Theo bai ra: , ;
»A!_=-^4fr^ = 0,46 ( m o l ) ; iiy = = 0,06 ( m o l ) .
27 22,4
Phíiii loui vii pliif(fn^ phap i^icii iiiuinii tsj tioci iioc /z -L.il i luinii i oan
G o i X , y Ian lifot la so m o l N^O, N j .
x + y = 0 , 0 6 4 4 x + 2 8 y
Ta c6: I X = 0,03
• - 1 S . 2 • I y = 0 , 0 3 X + y
Cac qua t r i n h cho - nhan electron:
A l - 3e > 0,46 > 1,38 m o l In,,,„„= l , 3 K ( m o l ) . + iOe 0,3 11 , + 5 2 N + 8e + 1 2 N 0,03 ( m o l ) 0,24 <- 0,03. 2 ( m o l ) ^ Sn,.„„„„ = 0 , 3 + 0,24 = 0,54 < 1,38.
Suy ra, c 6 qua t r i n h : N + 8e > N (NH4NO,)
( 1 , 3 8 - 0 , 5 4 ) - > 0,105 ( m o l )
Chát ran g 6 m C O A 1 ( N 0 , ) , (0,46 m o l ) va N H 4 N O , (0,105 m o l ) . V;)y m = 0,46. 213 + 0,105. 80 = 106,38 ( g a m ) .
D a p a n d u n g la H. 6. H o a tan het 7,74 g a m h6n hcfp bot M g , A l bQng 5 0 0 m l d u n g d i c h h 6 n hap HCl
I M va H : S 0 4 0 , 2 8 M t h u dirge d u n g d i c h X va 8,736 lit k h i H . ( 6 d k t c ) . Co can d u n g d i c h X t h u dugc l u a n g m u o i khan la