Cau 3. Dap an dung la C.
S6' mol KOH c6 trong 2 dung dich sau khi pha tr6n: 400.2,5 400 , ^ , . 400.2,5 400 , ^ , .
+ .1,2 = 1,43 (mol). 1000.1,05263 1000 1000.1,05263 1000
The tich dung dich sau khi pha trpn: 400 400
1,05263 + 400 = 780 ml hay 0,78 (lit) ^ C j K O H ) = ^ = 1,833 (M). ^ C j K O H ) = ^ = 1,833 (M).
2. T I J L U A N
a) Phuong trinh hoa hpc:
HjSO, + 2K0H -> KjSO, + 2H2O (1)
b) Mu6'i tao thanh la K2SO4.
Theo (1): S6 mol K2SO4 = s6' mol H2SO4 = 0,2.0,5 = 0,1 (mol). = 0,2.0,5 = 0,1 (mol).
Kh6'i lupng muoi K2SO4 la: , ,^
m = 0,1. (2.39 + 32 + 64) = 17,4 (gam).
c) Theo (1): so mol KOH = 2 s6' mol H2SO4 = 0,2 (mol) Khoi lupng KOH = 0,2.(39 + 17) = 11,2 (gam). Khoi lupng KOH = 0,2.(39 + 17) = 11,2 (gam). Kh6'i lupng dung djch KOH 16% la:
100
m,,=ll,2.—= 70(gam). 16
De so 1.3
^ T R A C NGHIEM K H A C H Q U A N
Cau 1. Dap an dung la B. .jiị: f
Cau 2. Dap an dung la B.
Phan ling s6' 2 va s6' 5 khong xay ra vi Fe va Al bi thu đng hoa trong H2SO4 dac ngupi va trong HNO3 dac, ngu6ị H2SO4 dac ngupi va trong HNO3 dac, ngu6ị
Phan ling s6 3 va s6' 4 kh6ng xay ra vi kim loai tu do hoat dpng yg'u hon
Icim loai trong mudị
Cau 3. Dap an diing la C. Phuong trinh hoa hpc: Phuong trinh hoa hpc:
Zn + FeSO, -> ZnSO, + Fe (1)
Gpi X la so mol Zn da phan ling tao thanh x mol Fe bam vao thanh kem.
Vi My^ > Mp^ ntn khd'i lupng thanh kem giam. Nghla la: 65x -56x = 13 -12,55 ^ x = 0,05 (mol) Nghla la: 65x -56x = 13 -12,55 ^ x = 0,05 (mol) Vay khoi lupng Zn phan ting la:
=0,05.65 = 3,25(gam). ^JU> -
2 . T I ; L U A N S
Phuong trinh hoa hpc:
Fe + MS04->FeS04+M (1) Gpi X la s6' mol Fe phan ling. Gpi X la s6' mol Fe phan ling.
Theo (1): S6' mol MSO4 = s6' mol Fe = x (mol).
" j(M + 96).x = 3,2 úombe:(l)o»riT M.x-56.x = 0,14 M.x-56.x = 0,14
Giai he phuong trinh dupe: x = 0,02 (mol). f"
- > M ^ , , = ^ = 160(gam) H
M + 96 = 160 ^ M = 64 -> M la Cụ CTPT ciia mu6'i sunfat la: CUSO4. CTPT ciia mu6'i sunfat la: CUSO4.
Ta c6:
De so 1.4
T R A C NGHIEM K H A C H Q U A N 411^! =
Cau 1. Dap an dung la C.
- Gia thiet 1 va 2 cho biét: A, B diing trudfc H; C, D diing sau H ^ A, B hoat dpng hon C, D. hoat dpng hon C, D.
- Gia thiet 3 cho biét: B hoat d6ng hon Ạ ;••