- Giai doan tiép theo cung dupe thife hien trong 16 th6i nhung ngimg th6i khi O, vao 16 Ket qua la dong (I) trong C u O va CU2S bj luru huynh 6 darg sunfua khijf
1. D5n m3u khi thai cua m6t nha may qua dung djch Pb(N03), du thi tháy xuát hidn ket tiia mau den Hidn tuong do chiJng to trong khi thai nha may c6 khi nao sau daỷ
tiia mau den. Hidn tuong do chiJng to trong khi thai nha may c6 khi nao sau daỷ
ẠH,S B.CO, C. NH3 D.SO2
Hu&ng dan gidi H O I -i-
Trong khi thai nha may CO H,S:
H2S + Pb(N03)2 ^ P b S i + 2 H N 0 3 l ) - ' '
den
Dap an dung la Ạ 2. Hoa tan 25 gam h6n hop X gom FeS04 va Fe,(S04)3 vao nuoc, thu duoc 150 ml dung djch Ỵ Them H,S04 (du) vao 20 ml dung djch Y r6i chu^n d6 toan b6
dung djch nay bang dung djch KMn04 0,1M thi dung het 30 ml dung djch chudn. PhSn tram khai luong FeS04 trong h6n hop X la
Ạ 13,68%. B. 31,6%. C.9,12%. D. 68,4%.
Hu&ng dan gidi tiCl
Dung djch chudn la KMn04 : n^^^^^ =0,03.0,1 =0,003mol
10FeSO4 + 2KMn04 + 8H2SO4 5Fe2 (804)3 ^ ^2^04 + 2MnS04 + 8H2O
0,015 <-0,003(mol)
=i> Trong 20 ml dung djch Y CO 0,015 mol FeS04
=> Trong 150 ml dung djch Y c6 0,015. 150/20 = 0,1125 mol FeS04 = > n i F e S O 4- 0 ' l l 2 5 . 1 5 2 = 17,l(g)
V a y % . . . 4 / x = ^ ^ 6 8 , 4 %
Dap an diing la D.
3. Dung djch A chura dong thori cac anion Fé^^.Al^^ . Trinh bay each taeh va nh&n
bid't m 6 i ion tir dung dich A .
Huong đn gidi
* Taeh: Cho dung djch N a O H den d u vao dung dich chura h6n hop Fe"*, h?*
. F e 2^ + 2 0 H " > F e ( O H) 2 i • ••'^•:„r\:-,
; A l ^ + + 4 0 H - > A I O 2 + 2 H 2 O '
" - L o c taeh icet tiia Fe(OH)2, r6i hoa tan vao axit se thu duoc Fe"*:
; F e ( O H) 2 + 2 H ^ )• Fê^ + 2 H 2 O ' I ; L, „ - Cho C O , d u vao phSn nu6c loc:
' C O , + 2 H 2 O + N a A l O j > A l ( O H ) , i + N a H C O , . , ;Cv.,
Loc taeh Al(OH)3, roi cho vao axit:
A l ( O H) 3 + 3 H ^ > A l ^ ^ + 3 H 2 O
* N h a n b i ^ : ^ ^
- Cho dung dich N a O H dir vao, xuat hi6n icet tua mau xanh trang, dị trong khong khf chuyen sang mau nSu do, ehiing to c6 ion Fe"*:
Fê^ + 2 0 H ~ > F e ( O H)2 i (trSng xanh)
4 F e ( O H)2 + O2 + 2 H 2 O > 4 F e ( O H) 3 i (nau do)
- Sue khf C O , vao nude loc thu duoc ket tua keo trdng, ehiing to c6 ion A l ' * NaA102 + C O 2 + 2 H 2 O > A 1 ( 0 H) 3 4 + N a H C O , .
4. Co 5 dung djch rieng re, m 6 i dung dich chiia 1 anion: N H 4, M g 2^ , F e ^ ^ , A i ' ' ^ , N a ^ , nong d6 khoang 0 , 1 M . Bang each dung dung N H 4, M g 2^ , F e ^ ^ , A i ' ' ^ , N a ^ , nong d6 khoang 0 , 1 M . Bang each dung dung dich N a O H cho iSn luot vao tirng dung dich, c6 the nhan bid't duoc t6'i da:
A . Dung djch chua ion: N H 4
B. Hai dung djch chu-a ion: N H 4 va A l ^ ^ ' ' ' '
C. Ba dung djch chiJa ion: NH;,Fe-^+ va Ar"*^
D. Nam dung djch chiia ion: N H 4 , M g ^ " ' , F e - ^ \ N a " ' , A l ^ ' ' .
Huong đn gidi
\; + O H - — ^ N H 31 + H 2 O
' k h i , m i i i khai
I . Mg^"" + 2 0 H " > M g ( O H) 2 i
trang ,
CtyTNHH MTV ir \ Khang Viet
Fc^^ + 3 0 H - > F e ( O H ) 3 i " ' do nau Al^+ + 3 0 H - > A l( O H ) 3 i ^ A l( O H ) + O H - > A I O 2 + 2 H 2 O -••'-ir!, ..Ọ', ii- Na"' + O H " : Kh6ng xay rạ V j ,
=> Nhan bi^'t duoc ca 5 dung djch. D a p an dung la D .
5. Co 2 dung djch rieng re chiia cac anion: N O J ; C O | " . Hay ntu each nhan bifít ti^ig ion trong dung djch dọ Viet cac phuong trinh hoa hoc. ti^ig ion trong dung djch dọ Viet cac phuong trinh hoa hoc.
Huong đn gidi ,, ..^.^
* Nhan bia ion C O 3 " : Dung axit manh
2H+ + C O ^ - > C O 2 t + H 2 O
* Nhan bie't ion NO3 : Dung b6t Cu va axit H2SO4
2 N 0 ; + 3Cu + 8H+ > 2 N 01 + 3Cu^^ + 4 H 2 O 2 N 0 + O2 > 2 N O 2 (mau nau)
6. Co dung djch chiJa cac anion C O 3 " va S O 4 ". Hay ndu each nhan bid't tirng ion trong dung djch. Viet cac phuong trinh hoa hoc.
Hu&ng đn gidi • '>>
* Nhan biet ion C O 3 " : Dung axit manh:
C O 3 ' + 2 H * > C O 2 t + H 2 O /
* Nhan biet ion SÔ": Dung Bâ^ / H^
5 0 4 " + Bâ"" > BaS04 i (trdng)
7. Co 5 dung dich hoa cha't khong nhan, m6i dung djch nong d6 khoang 0 , 1 M ciia
mot trong cac mu6'i sau: K C l , BaCHCOj),, K ^ C O , , K . S , K2SO4.
Chi dung dung djch H2SO4 loang, nho true tiep vao timg dung djch, thi c6 the
nhan biet duoc t6'i da nhOng dung djch naỏ §;c
A . H a i d u n g d j e h : B a( H C 0 3) 2, K 2 C 0 3 ''^
B. Ba dung djch: B a( H C 0 3 ) , , K 2 C 0 3, K 2 S * : ^ ,
C. Hai dung djch: B a( H C 0 3) 2 , K 2 S >, • - ; i , 8, i : , r
I, }•:.
Huong dan gidi
H2SO4 + KCl > Kh6ng xay ra
H2SO4 + B a ( H C 0 3) 2 >BaS04 i +2CÔ t +2H2O
H 2 S O 4 + K 2 C O , > C O 2 t + K 2 S O 4 + H 2 O H 2 S O 4 + K 2 S > H 2 S t+ K 2 S 0 4
khi mui triing thoi
MMiXith- H 2 S O 4 + K 2 S O 4 : Khongxay rạ SdK
it' Vay chi nhan biet dirge tdi da 3 dung djeh: BăHC03)2 ; K 2 C 0 3; K 2 S 1^' i Dap an dung la B.