- Hoatan het phd n2 bang dung dich HNO3 dac, nong (du) tháy c6 11,76 lit khi bay ra (dktc).
1. Dien phan AUO, nong chay vdi dong dien cuong dp 9,65A trong thofi gian 3000 giay
thu dupe 2,16 gam A l . HiSu suát eua qua trinh dien phan la
Ạ 60%. B. 70%. C. 80%. D. 9 0 % .
Huong đn gidi
Tir cong thiic Faraday, tinh dupe khdi lupng A l theo If thuyet: ẠỊt 27.9,56.3000 ^ ^/ ,
" = 3.96500 ^^3
Vay hieu suát ciia phan ting dien phan
H % = ^ : i ^ . 8 0 % . '
Dap an dung ia D. 2. Dien phan 20,4 tán AUOj nong chay (eo criolit, cac dien cue bang than chi), o
anot xay ra phan ling phu tao thanh h6n hpp khi CO va CO, (h6n hpp c6 ti khoi
so vai khi H , bang 16,67). Kh6'i lupng than chi a anot da bi hao hut la (hieu suát
qua trinh dien phan dat 100%)
Ạ 4,50 tan. B. 26,5 ta'n. C. 24,36 ta'n. D. 5,40 ta'n. Hu&ng đn gidi Theobaira: n = ^ " ' ^ ' ^ z.0,2.10\mol) A I 2 O 3 102 PTDP: 2A1,03 > 4A1 + 3 0 , t 0,2.10\mol) 0,3.10 V o l )
Phan ling dot chay b anot:
C + O 3 > CO,
Phan logi va pliife/ng phap i^iai nlian/i HI Hoa hoc IZ - C M / i:>!nJi I oun 2C + O2 y y/2 -> 2CO y (mol) Taco: X + ^ = 0,3.10^ 2 44x + 28y x + y = 16,67.2 = 33,34 X =0,15.10*' y = 0,3.10^ Vay: mc = 12(x+y) = 12. (0,15 + 0,3). 10* = 5,40. 10* (gam) = 5,40 tán. Dap an dung la D.
3. Dien phan nong chay AUO, vori anot than chi (hieu suát dien phan 100%) thu
duoc m kg A l & catot va 67,2 (a dktc) h6n hop khi X c6 ti khd'i so vdi hidro
bang 16. Lay 2,24 lit (d dktc) h6n hop khi X sue vao dung dich nirotc v6i trong (dir) thu diroc 2 gam ket tiiạ Gia trj cua m la
Ạ 108,0. B. 67,5. C. 54,0. D. 75,6.
Hu&ng đn gidi
67,2.10' Theo bai ra: nx =
riv = 22,4 2,24
= 3.10Mmol).
22,4
Cac phuong trinh hoa hoc xay ra:
= 0,1 (mol); nc,co34 = ] ^ = 0 ' 0 2 ( m o l ) . A l . O -> 2A1+ - 0 , t 2 (*) C + O, 2C + 0 . -> CO, 2C0
CO, + CăOH)2 (du) > CaCOj i + W.O
Trong h6n hop khi c6 thé c6 cac khi sau: CO, (x mol), CO (y mol) va O, (z mol). x + y + z = 3000 (1)
44x + 28y + 32z = 16.2 Theo bai ra, ta c6:
x + y + z
=> 44x + 28y + 32z = 96000 (2)
Khi 0,1 mol X + Că0H)2 du > 0,02 mol CaCOj (0,02 mol CO,) 3000 mol X z mol CÔ
=> z = 6C0 (3) Tir ( 1 , 2, 3) ta giai ra diroc: x = 600; y = 1800; z = 600.
Cty TNHH MTV DVVH Klumy, \
Suy ra, tcng s6' mol khi O, sinh ra theo phiromg trinh (*) (ap dung bao loan
nguyfen t o o x i ) : ,
2]no2 = x + ^ + z = 6 0 0 + + 6 0 0 = 2100 (mol) ; 2100.2.27 . . J ' : - ^
VI H = 100% ^ m^, = — = 75600 (g) = 75,6 (kg). , , ; , „
Dap an dung la D. Dang 12: Bai tap nhan biet, tach cac cliat
1. De phan biet 3 m5u hop kim rieng biet sau M g - A l ; M g - K; M g - A g , c^n dung them t6'i thiéu
Ạ 1 hoa chat. B. 2 hoa chat. C. 3 hoa chat. D. 4 hoa cMị
Hu&ng đn gidi
De phan biet 3 mSu hop kim (Mg - A l ; M g - K; M g - Ag) cin diing them t6'i thiéu 1 hoa chat la H , 0 :
M g - K + H , 0 > M g + K O H + - H , t
2 uib
Cac hop kim con lai khdng tac dung vdfi H , 0 .
Cho cac hop kim con lai vao dung dich K O H vCra thu duoc:
2Mg - A l + 2 K O H + 6 H , 0 > 2Mg + 2K[A1(0H)4] + 3H2T
Con hop kim M g - A g khdng c6 hien tuong gị
Dap an dung la A . 2. Cac dung dich ZnS04 va A I C I 3 d^u kh6ng maụ Dé phan biet 2 dung dich nay
khong the diing dung djch
ẠBăOH),. B.NH3. C B a C l , . D. NaOH.
Hu&ng đn gidi
Xet cac phuong an: Ạ Duoc, v i :
ZnS04 + 2Bă0H),,d„, > BsSO, i + Ba[Zn(0H)4] * t
2Aia3 + 3BăOH), > 2Al(OH)3|+3Baa,
BăOH),(du) + 2A1(0H)3 > Ba[Al(0H)4],
B. Duoc, v i :
2NH3 + ZnS04 + 2 H , 0 > Zn(OH)2 i + (NH4),S04 , , , , > 4NH3(^> + Zn(OH)2 > [7n(m^mO\i)^ *
AlCl, + 3NH3,du, +3H,0 > A l ( O H) , 4 , +3NH4a 5 C. Dufoc, vi:
BaCl2 + ZnS04 > BaS04| +Zna2
BaCl, • ; -A I C I 3 > khong phan ling.
D. Khong diroc, vl: ^ ' " ' ' 2NaOH + ZnS04 > Zn(OH):i +Na2S04
^ 2NaOH (du) + Zn(OH), > Na,[Zn(OH),]
3 N a O H + Aia,, > Al(OH), i + 3NaO NaOH (du) + Al(OH)., > NalAl(OH)4]
Dap an dung la I). 3. Co cac dung dich: KNO,, Cu(NO,)2, FeCl,, A i d , , NH4CỊ De c6 th^ nhan biet
duc«c cac dung djch ridng biet trdn cSn dung thu6'c thij la: Ạ dung djch NaOH dụ B. dung djch AgNO,. C. dung dich Na,S04. D. dung djch HCl.
Hu&ng đn gidi
Can dung thuoc thif la dung dich NaOH du: KNO, + NaOH > khdng phan ihig.
CuCNOj), + 2NaOH (du) > C u ( O H ) , i +2NaN03. trSng xanh duong
Fea, + 3NaOH(du) > Fe(OH),4 + 3NaCl do nau
AlCI, + 3NaOH > A K O H ) , ! +3Naa trdngkeo
AKOH), + NaOH(du) > Na[Al(0H)4]
tan
NH4a + NaOH — ^ NHjt + NaQ + H,0
Dap an dung la Ạ