D: 2m Ilgaoi ta chi€u d6ng thdi hai buc
Vi kh6i lugng chdtrfun sau phin rmg bing
nhau n6n ta c6: 8.V1.7: 80.V2.0,1 Rrit ra Vt: Vz. @6p 6n dung: C). n
*Thi dU 6. (DC bhi Id Thi du 2)
Ldi gidl Theo c5c phin img (3, 4) ta th6y, cri
1 mol ancol clon chric UAt ti chuy6n thAnh este
cua axit axetic kh6i luqng tdng:
McH,coon - Mnon : 59+R - R-17 = qZ(g) Do <16, k:hOi luqng este t[ng 42.0,2: 8,4 (g)
so vor ancol ban diu.
YQy Lmssls:7 ,8 + 8,4: 76,2 (g).
I??este thuc 4;: 16,2.0,7 : 11,34 (g).
3. Phu'ong phnp kh6i lrr-oug phf,n tii'trung
binh M
DAy ld phucrng ph6p hay nhAt, rlugc ung dUng
,!,
rong rEi nhdt cho c6c bii to6n h6n hqp rdn, 16ng, khi vd ttuoc m0 r6ng sang c6c phuong ph6p trung binh kh6c nhu s6 nguy€n tu cacbon,
hiclro trung binh,. ..), cdc nh6m (-OH, -NOz,
{OOH, ...) trung binh, c6c g6c hidrocacbon trung binh n. U phuong ph6p ndy qu6 quen thu6c vd da dC cflp b cbc bdi b6o tru6c n6n 6
dAry 6c gi6 kh6ng n6u c6c thi dp nta.
4. Phu'ang phfp b:lo toin clectron
NQi dung cria phucmg ph6p: trong h6n hqp c6 nhi6u ch6t oxi ho6, nhi0u ch6t khri tham gia ph6n img thi t6ng s6 mol electron c6c ch6t khir
cho ph6i bing t6ng s6 mol electron cfuc chdt
oxi ho6 nhfln. tlu cti6m cta phucrng ph6p ndy
ld kh6ng cAn vii5t vd cdn bing phucrng tdnh
phin img; nh.mg quan trgng nh6t h ph6i x6c dinh dring trang th6i dAu vd trang th6i cu6i cua cdc chdt oxi ho6, ch6t khu. Phucrng phrip ndy
tb rardtdqn lcr-r khi kh6ng bi6t rO h5n hqp g6m nhirng ch6t gi, thf t.u phin img nhu th6 ndo.
TOAN HQC. ....
- cfudiUa
*Thi dg 7. I{od toru 18.5 gam hon hop Fe. Fe3Oa bang 200 ml rhmg dir* HNOj a mol/l
tht dnor: tltmg dich X;2.24lit NO (,san phdnt
khr tla' nltdt. o dktc) t:a cdn lai 1,46 gam kim
loai. Tinh a vt) khoi ltrong ntuoi trong X.
Loi gidi
Tr4ng th6i dAu Trpng th6i cu6i
0+2
Fe + Fe+ 2e (v\ dukimloaiFe)
+2 +3 +2
!e, ,2Ee+2e -+ 3FeFqo4 Fqo4
+5 +2
N+3e -+ N
Ta c6 phucrng trinh bAo todn electron
2n:2m + 3.0,1
vd phuong trinh b6o toan kh6i lugng 56n + 232m + 1,46: 18,5.
Giei hC phuong hinh ta c6 n: 0,18; m: 0,03. T6ng s6 mol mu6i Fe(NO3)2 ld
n't 3m: 0,18 + 3.0,03 : 0,27 (mol)
t<hOi luqng mu6i Fe(NO3) ld 027.180:48,6 G).
sd mol axit tao mudi + sd mol axit tao NO
a:'
thdtich
0,27 .2 + 0,1
=3,2M. J
*Thi d,,r tl. I{in lryp X gont FeO, Fe203,
Fe3Oa. Cfut khiC.O qrra ong .sti'dung nt (gatn)
X ntmg rt6ng. stttt rnot thd'i giun ihu clrrqt'r. hin
hop t'hat rtin Y o'tt'ong ong sti't,t) hin trop khi Z di i'u khoi 6ng. Cho todn bo kh{ Z t,do tlung dic:lt Ca(OH')2 du', sau phan tittg hodn todn thtt tfiro't' 1 gan k€t titu. Mtit khdc,. hod tan hodn todtt Y trong dung dich II2SOa rliit', nong (du) thu dtroc i,008 lit khi SO2 (san pham khrc duy nhat, dktr:) va thtng clir:h ch*a 18 gam mudi. Gid tri cttu m ld