D. diing bang nong dp ciia dung djch chat c^n xac djnh.
Huong đn gidi
Khi chuan dp de tranh nhirng sai s6' 1dm, ngucfi ta dung cac dung djch chuan cd n6ng dp gan vdri nong dp ciia dung djch chat cdn xac djnh.
Dap an diing la C. 40. Chát chi thj axit - bazo ciia m6i phan iJng chu^n dp axit - bazo cu th^, khong
CO dac diem:
Ạ La axit huu co hoac bazo hỉu co yéụ ' ' 4
B. Cd mau sdc ciia dang phan tir va ciia dang ion khac nhaụ , ' C. Mau ciia chat chi thj phu thupc vao pH ciia dung djch.
D. Cd khoang pH doi mau nam ngoai pH ciia diem tuong duong.
Hu&ng đn gidi
De nhan ra diem tuong duong ciia phan limg chudn d6, ngucri ta dung chát chi thj gpi la chat chi thj axit - bazo hay chat chi thj pH. Do la axit hiJu co hoac bazo
hihi CO yéu ma mau sSc ciia dang phan tir va ciia dang ion khac nhau, n6n mau
ciia chat chi thj phu thu6c vao pH cua dung djch.
Dap an diing la D. 41. Co 5 dung dich mu6'i rieng biet: AlCI,, Fe(N03)„ FeS04, Mg(N03)2, NH4CỊ
Chi diing dung djch K O H cd the nhan biet dupe tdi da só dung djch la Ạ 1 dung djch. B. 2 dung djch. C. 3 dung djch. D. 5 dung djch.
... :>':•>' f{ ' !\
Phdn loai vci phifang phcip gidi nluinh BT Hoa hoc 12 — Cu Thanh Toan Hu&ng dan gidi Hu&ng dan gidi
PTPU" cua cac dung djch mu6'i v6i K O H : r i
AICI3 + 3 K O H > Al(OH).,i + 3KC1
A K O H ) , + K O H( d u ) > K[Al(OH)4] (tan) Fe(NỌ0,i + 3 K O H > Fe(OH)., i + SKNO,
, do nSu
FeS04 +2KOH > F e ( O H ) . i + K2SO4 trSng xanh
^ ' MgCNOj)^ + 2 K O H > M g l O H ) , ! + 2KNO3
I fM- H . trdng
NH4CI + K O H N H, T + K C l + H , 0 mui khai
=> Co the nhan biet ducrc tat ca 5 dung dich. Dap an diing la 1). 42. Co bon binh hoa chat mat nhan, m6i binh chira mot trong cac dung djch sau:
Na:S04, NâCO,, BaCK, K N O , (vdri nong d6 ichoang 0,1M).
Co the phan biet cac dung djch tren bang mot thudc thir duy nhát la
Ạ quy t i m . B. bac nitrat. C. bari hidroxit. D . axit sunfuric.
Hu&ng dan gidi
Thuoc thir do la quy tím. That vay:
- Cho quy t i m vao cac mau thir, mSu lam quy tím hoa xanh la NajCO,: NâCOj > 2Nâ + CO3-" (adsbygoogle = window.adsbygoogle || []).push({});
CO3-" + H O H < i i HCO,- + 0 H "
M 6 i tnrofng ki6m (OH") lam quy t i m hoa xanh. Cac mSu con lai (cac mudl tao tir axit manh va bazo manh) kh6ng lam d6i mau quy tim (moi tnr6ng trung tinh). - Cho NâCOj vao cac m3u thir 3 dung djch con l a i , mSu tao ra ket tija trdng la BaCU:
BaCU + NạCOj > B a C O j i + 2NaCl trang
. ' NạS04 + NâCOj
v « , , KNỌ, +Na3C03
- Cho BaCli vao 2 mdu thir con lai, mau tao ra ket tua trang la mSu chiira Na2S04: BaCK + Na2S04 > BixSO.i + 2 N a a
trdng • K X i J ' ' K N O 3 + B a C U
MSu con lai la KNO3. Dap an diing la A-
43. Chi diing th6m m6t thu6'c thir d^ phan biet b6'n dung djch dimg trong cac binh khong CO nhan: N H 4 a , (NH4)2S04, B a d , , NaOH, Na,C03, thuoc thir do c6 th^ la khong CO nhan: N H 4 a , (NH4)2S04, B a d , , NaOH, Na,C03, thuoc thir do c6 th^ la
Ạ nu6c v6i trong. B. quy tfm. C. bac nitrat. D . kali hidroxit.
Huong đn gidi
Co th^ dung thuoc thir: quy t i m . ' '''"'U;vU » ạ'.'-f
- Cho quy t i m vao cac m3u thir:
+ Mau lam quy t i m hoa do: NH4CI, (NH4)2S04 (nhom I ) m
+ MSu lam quy t i m hoa xanh: NaOH, NạCO, (nhom I I )
+ Mau khong lam doi mau quy tfm: BaCK. ,
- Cho BaCU vao 2 mSu thir 0 nhom I :
+ Mau tao ra kS't tiia trang la (NH4)2S04:
B a d , + (NH4)2S04 > B a S 0 4 i + 2 N H 4 C I
BaCK + NH4CI X > + MSu con lai chiia NH4CỊ
- Cho BaCU vao 2 m3u thir a nhom I I :
+ MSu tao ra kd't tiia trang la Na2C03:
BaCl, +Na2C03 — ^ B a C O , ! + 2NaCl ... B a C l , + N a O H
+ MSu con lai la NaOH.
Dap an dung la B . 44. Co bon goi chat ran ridng biet: Fe, Fe.Oa, Fe304, F e O . Chi dung them axit
HNO3 dac, CO the nhan biet dirge
Ạ Fẹ - B. Fe,Fe304. C . Fe, Fe.O,. D. Fe, F e O .
Hu&ng dan gidi
PTPÚ: Fe + HN03(dac, ngu6i) > khong phan ung.
Fe^Oj + 6HNO3 > 2Fe(N03)3 + 3H3O (adsbygoogle = window.adsbygoogle || []).push({});
Fe304 + 10HNO3(dac) > 3Fe(N03)3 + NÔT + 5 H , 0 j,^ j (nau)
F e O + 4HN03(dac) > Fe(N03)3 + N O , t + 2H2O
Suy ra, c6 the nhan ra dugc Fe va Fe203.
Dap an dung la C . 45. Co 6 dung djch rieng biet: K C l , KNO3, K2S, K3PO4, K B r , K I . Co the nhan biet
cac dung dich tren bang m6t thud'c thir la j ' Ạ sat(III) cloruạ B. axit sunfuric loang.
C. k h i c l o . D . bac nitrat. , .
Hu&ng đn gidi ' 7 ,
Thudc thir do la AgN03:
KCl + AgNỌ, > A g C l i + K N U ,
trang
XNO3 + A g N O j > khong phan ling.
K,S + 2 A g N 0 3 > A g , S i + 2KNO,, „ „ i,„ . K3PO4 + SAgNO,, > A g , P 0 4 i + 3 K N O 3 vang KBr + A g N O , > A g B r i + KNỌ, '' vang nhat K I + A g N O j > A g l i + KNO3 vang 2AgI 2 A g ; + I , den Dap an dung la D.
Chit v.- AgCl, AgBr, A g l deu de dang bi phan huy ngoai anh sang, tao ra chát ran mau den (bot Ag).
46. De lam sach khi CO, lan khi SO,, c6 the dung
A . nu6c v6i trong. B. nude brom.
J C. dung dich natri hidroxit. D. voi b6t.
ijV, Huong dan gidi
CO2 va SO2 dau la oxit axit (tac dung vdri kiem, oxlt bazo,...), SO, c6 tinh khir
(tac dung v6'\g djch Br,) con CO, khong c6 tinh khiJr. Do do c6 the loai khi
SO, ra khoi h6n hop khi vdi CO, bang nude brom (du): SO, + Br, + 2 H , 0 > H,S04 + 2HBr CO, + B r , + H , 0
Dap an dung la B. 47. Khi diau che CO, tir da voi va axit clohidric, khi CO, thu dugc thucmg c6 ISn
tap chat HCl. Cach tot nhat de loai irii tap chat HCl la cho khi thu duoc di qua
Ạ dung dich NaOH dụ B. dung dich A g N O , dụ C. dung dich NaHCOj dụ D. nude cat.
Huong đn gidi
Cach tot nhát la dung dung dich NaHCO, du:
HCl + NaHCO, > CO,T + NaCl + H , 0
Dap an diing la C.
Chu v.- - Khdng dung nude cat, tuy HCl tan tot trong nude, con CO, tan rat ft trong nude, nhung CO, se loi cudn HCl di theọ
- Khong dung dung dich A g N O , v i :
294 (adsbygoogle = window.adsbygoogle || []).push({});
HCl + A g N O j > A g C l i + HNO3
CO, se loi cu6'n H N O , di theọ
148. Cho cac cation: NH4 , N i " * , Cá*, Na*. Ngudi ta khong dung phan ling hoa hoc
d^ nhan biet cation 1
A . N H ; . B . N i ^ ^ C.Câ^ -^^i^^^, D. Na\
Huong đn gidi
HSu hat cac hop chat ciia natri tan nhieu trong nude va khong cd m^u, nen ngudi
ta khong dung phan ling hoa hoc de nhan biet ion Na* ma dung phuong phap vat
ly thir mau ngon lira nhu sau: T^m ft bot mudi rdn hoac dung djch mudi natri len day platin roi dua day do vao ngon lira den khf khong mau, ta se tháy ngon lira nhudm mau vang tuoị
Dap an dung la D. 49. Khong the dung phuong phap kát tiia d^ nhan biát anion
A . nitrat. B. sunfat. C. cloruạ D . cacbonat.
Huong đn gidi
Phuong phap kát tiia chi cd the thuc hien duoc khi cd sir tao thanh chat khong
tan. Ma thuc te, tat ca cac mudi nitrat d^u tan tdt trong nude, do đ khong the
dung phuong phap ket tiia dá nhan biát ion N O , ' .
Dap an dung la Ạ
CM y; - Phuong phap ket tiia dugc dung de nhan biát cac anion:
Cr + Ag* > A g C l i (trang).
CO3-" + Ca-* > C a C O j i (trdng). ' , '
SO4-- +Ba-* > BaS044 (trang). - Cd the nhan biet ion NO," bang Cu/ H * :
3Cu + 2NO3- + 8H* > 3Cu-* + 2 N 0 + 4 H , 0 xanh
2NO + O, > 2 N 0 , (nau).
50. Kát tiia hidroxit k i m loai cd mau trdng hcri xanh la
A . F e ( O H ) , . B.Cu(OH),. C. Ni(OH),. D. Mg(OH),.
Huong đn gidi
Mau sac cua mot sd hidroxit kim loai: - Fe(OH),: Mau trdng hoi xanh. - Cu(OH),: Mau xanh.
- N i ( O H ) , : Mau xanh luc.
- M g ( O H ) , : Mau trdng. ^