Phan dgng phuong ph^p giai H6a hgc 11 V6 cO - D8 Xuan Htflig
them mot it dung djch NaOH ntJa neu thay dung djch c6 m^u hong Ih H3PO4,
con hii la dung djch H 2 S O 4 khong hiOn tiTcfng.
B a i 3. Rau qua kho dÚcJc bao quan bhng khi SO2 thi/dng chtfa mot liTtJng nho
hdp chát CO goc S O 3 " . De xac dinh suT c6 mat cua cac ion SO3" trong rau qua, mot hoc sinh ngam mot it qua dau trong niTdfc. Sau mot thcli gian Ipc lay dung dich roi cho tac dung vdi dung djch H2O2 (chát oxi hoa), sau do cho tac diing ticp vdi dung djch B a C l 2 . Viet cac phiTcfng trinh ion rilt gon da xay rạ
Gidi
PhiTdng trinh ion rut gon : S O ^ + H2O2 > SOJ- + H2O
Bâ* + S O 4 " > BaS04>l'
Bai 4. NhuTng hoa chat sau thi/clng di/dc dung trong cong viec noi trcJ : muoi an, giam, bot nd ( N H 4 H C O 3 ) , phen chua (KAI(S04)2.12H20), muoi iot (NaCl + KI). Hay dilng cac phan iJng hoa hoc de phan biet chiing. Viet phiTtfng Irinh ion riit gon cua cac phan tfng.
Giai
Cho cAc chat tren vao nxidc de dufcJc cac dung dich :
* Dung djch muoi an (NaCl)
Cho dung dich AgNOs vao muoi an -> hien ti/cfng A g C l i trang. Ag* + Cr > A g C l i
* Giam ( C H 3 C O O H )
Cho CaC03 vao c6 hipn tifdng sui bot khị
2 C H 3 C O O H + CaCOj > ( C H 3 C O O ) 2 C a + C O . t + H2O
* Bot nS ( N H 4 H C O 3 )
Cho dung djch NaOH vao -> khi, mui khaị
N H ; + O H - > N H j t + H2O
* Phen chua (KAI(S04)2.12H2O)
Khi hoa tan phen chua v i o niTdc c6 ket tua keo trttng xusít hien. PhiTcJng trinh ion rut gon:
A l ' * + 3H2O ^ A l ( 0 H ) 3 i + 3 H *
* M u o i iof ( N a C l + K I )
Cho chat oxi hoa H2O2 vao -> c6 hi<?n ti/cJng h sinh ra lam cho ho tinh bot c6
mau xanh.
Phi/cJng trinh ion rial gon: 2 r + H2O2 > h + 2 0 H - .
Bai 5. V i c t cdc phuTcfng trinh phan lit \k ion riit gon cua cac phan iJng (neu c6)
xay ra trong dung djch giiJa cdc cap chat sau :
a) Fe2(S04)3 + N a O H b) N H 4 C I + AgN03 c) NaF + H C l d) MgCl2 + K N O 3
e) FeS + H C l i") K O H + HCIỌ
Gidi
a) Fe2(S04)3 + 6NaOH > 2Fe(OH)3i + 3Na2S04 Fê* + 3 0 H - > F e ( O H ) 3 i Fê* + 3 0 H - > F e ( O H ) 3 i
b) NH4CI + AgN03 > A g C l i + NH4NO3 Cr + A g * ).AgCl4^
c) NaF + H C l > NaCl + H F t F + H * > H F t
d) MgCl2 + K N O 3 > khong c6 phan tfng xay ra
e) FeS (r, + 2HC1 > FeCh + H2St
FeS + 2 H * >Fê^ + H2St
0 HCIO + K O H > KCIO + H2O
HCIO + O H " > CIO" + H2Ọ
Bai 6. Viet phiTdng trinh ion rut gon cua cac phiin tfug hoa hoc sau: (1) (NH4)2S04 + BaCl2 (2) CUSO4 + BăN03)2 ^
(3) Na2S04 + BaCl2 -> (4) H2SO4 + BaS03 -> (5) (NH4)2S04 + Bă0H)2 -> (6) Fc2(S04)3 + BăN03)2 ^
GiaM
(1) (NH4)2S04+ BaCl2 ^ 2NH4CI + BaS044' -> pt ion thu gon: Bâ"" + S04^' -» B a S 0 4 i (2) CUSO4 + BăN03)2 ^ Cu(N03)2 + BaS04 i
-» pt ion thu gon: Bâ* + S04^" -> BaS04 i (3) Na2S04+ BaCl2 - * 2 N a C l + B a S 0 4 i
-> pt ion thu gon: Bâ"^ + S04^" BaS04 i (4) H2SO4 + BaS03 -> SO2 + H2O + BaS04 i
-> pt ion thu gon: 2 H * + S04^" + BaS03 ^ SO2 + H2O + BaS04 i
(5) (NH4)2S04 + BăOH)2 -> 2 N H , + B a S 0 4 i + 2H20
-> pt ion thu gon: 2NH4* + S04^"+ Bá^+ 2 0 H - ^ 2NH3 + BaS04 i + 2H2O
(6) Fe2(S04)3 + 3BăN03)2 -> 2Fc(N03)3 + 3BaS04 i
H6a hQC 11 V6 CO - DS XuSn Hung
Bai 7. Trong cac ion sau: CHjCOO", CÔ", HCÔ, H S O 4 , CP, N H 4 ,
AKHzO)^", S^', Q H 5 O " , K"" la axit, bazd, trung tinh hay lU3ng tinh? T a i saỏ
Gidi
* Cac ion la axit : H S O 4 , N H 4 , AKHjO)^* v i chung c6 kha ming cho proton (theo Bronstet).
H S O ; + H2O ^ HjÔ + SÔ-
I *
N H ^ + H2O HjÔ + NH3
A 1 ( H 2 0) ' V H2O - > H3O* + Al(OH)'^
* Cac ion la bazd : CHjCOO", C O ^ , S^", CfH^Q- v i chung c6 kha nang nhan
proton (theo Bronstet).
C H 3 C 0 6 - + H 2 O C H 3 C O O H + O H "
C O 3 " + H2O H C O 3 + O H "
S^' + H2O -> HS" + OH"
CfiHjO" + H 2 O -> CfiHjOH + O H " (phenol)
* Cac ion la irung tinh : C r , K"^ v l chung khong cho cung khong nhan proton. * Ion la imlng tinh : H C O J v i viTa cho, viTa nhan proton
H C O 3 + HjÔ -> C O 2 + 2H2O HCO3 + H2O C 0 | - + HiO\
Bai 8. Viet phiTcJng trinh phan tuT, phÚcJng trinh ion rut gon cua ctic phan tfng sau:
a) CaCl2 +? > CaCOji +? c) BaC03+? >BăN03)2+? c) BaC03+? >BăN03)2+? e) FeCl3+? >KC1 +? b) Pb(N03)2 +? > P b C b i +? d) H P O ^ " + ? > - H 3 P 0 4 + ? Gidi
a) CaCl2 + Na2C03 > C a C O j i + 2NaCl C a ^ * + C O | - ^ C a C O j i
b) Pb(N03)2 + 2KC1 > PbCl2>t + 2 K N O 3
Pb^* + 2Cr >PbCl24'
c) BaC03 + 2HNO3 > Ba(N03)2 + CO.T + H2O
BaC03 + 2H* > Bâ* + C02t + H2O
d) CaHP04 + H2SO4 > CaSOA + H3PO4
e) FeCb + 3 K 0 H > F e ( 0 H ) 3 i + K C l Fê^ + 3 0 H - > F e ( 0 H ) 3 i . Fê^ + 3 0 H - > F e ( 0 H ) 3 i .
Bai 9.
a) Theo dinh nghTa mdi cua Bronstet. Cho quy tim vao cac dung djch sau se c6
mau gỉ CHjCOONa, Ba(N03)2. NH4CI, K2CO3? Gifii thich?
b) D i / doan dung dich cho difdi day c6 gia tri p H Idn hOn hay nho hcfn 7?
NazCOj, K C l . C H 3 C O O K , NaHS04. Al2(S04)3. Na2S, CfiHsONả
Gidi
a) Theo dinh nghTa m d i cua Bronstet: Axit la chát nhi/dng proton (H*), bazO Iti chat nhan proton.
* Cho quy tim vao dung dich CHsCOONa -> quy tim hoa xanh. V i : CHjCOONa )• CHjCOO" + Na*
C H 3 C O O + H 2 O C H 3 C O O H + O H "
* Cho quy tim vao dung dich Ba(N03)2 -> quy tim khong doi mau do khong bi thfiy phan.
* Cho quy tim vao dung djch N H 4 C I -
VT : N H 4 C I > N H | + Cr
N H ; ^ + H2O NH3 + HjÔ
* Cho quy tim vao dung dich K2CO3 -
V l : K 2 C O 3 > IK" + COJ-
quy tim hoa dọ
quy tim hoa xanh.
C O ^ + H 2 O -> H C O 3 + OH"
b) * Dung djch c6 p H = 7 : K C l
* Dung dich c6 p H < 7 : NaHS04, Al2(S04)3
* Dung djch c6 p H > 7 : C H 3 C O O K . Na2C03, NiXjS, CfiHsONạ
Bai 10. Chi dung quj' tim hay phan bỉt niim lo mat nhan sau: H C l , H2SO4, K C l , NaOH, BaCl2.
Gidi
~ L a y m o i l o m o t i t d e l a m m l i u t h i i f .