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\(2Al\left(a\right)+6HCl\rightarrow2AlCl_3+3H_2\left(1,5a\right)\)
\(Al_2O_3\left(b\right)+6HCl\left(6b\right)\rightarrow2AlCl_3+3H_2O\)
\(1,5a=\dfrac{13,44}{22,4}=0,6\Rightarrow a=0,4\left(I\right)\)
\(27a+102b=21\left(II\right)\)
Thay (I) vào (II) => b = 0,1
\(\Rightarrow\%m_{Al}=\dfrac{27.0,4}{21}.100=51,43\%\Rightarrow\%m_{Al_2O_3}=48,57\%\)
c) \(m_{HCl}=6.0,1.36,5=21,9g\)
\(\Rightarrow m_{ddHCl}=\dfrac{100.21,9}{7,3}=300g\)
\(\Rightarrow V_{ddHCl}=\dfrac{300}{1,03}\approx291,26ml\approx0,3l\)
Giải:
a) Số mol H2 ở đktc là:
nH2 = V/22,4 = 13,44/22,4 = 0,6 (mol)
PTHH: 2Al + 6HCl -> 2AlCl3 + 3H2↑
-----------0,4----1,2------0,4---------0,6--
PTHH: Al2O3 + 6HCl -> 2AlCl3 + 3H2O
----------0,1---------0,6-----0,2---------0,3--
b) Thành phần phần trăm khối lượng mỗi chất trong hh ban đầu là:
%mAl = (mAl/mhh).100 = (0,4.27/21).100 ≃ 51,4 %
=> %mAl2O3 = 100 - 51,4 = 48,6 %
=> mAl2O3 = (21/100).48,6 = 10,2 (g)
=> nAl2O3 = m/M = 10,2/102 = 0,1 (mol)
c) Khối lượng dd HCl tham gia pư là:
mddHCl = (mct.100)/C% = (1,8.36,5.100)/7,3 = 900 (g)
Thể tích HCl đã dùng là:
VHCl = m/D = 900/1,03 ≃ 874 (ml)
Vậy ...
\(a)2Al+6HCl\rightarrow2AlCl_3+3H_2\\ Fe+2HCl\rightarrow FeCl_2+H_2\\ b)n_{H_2}=\dfrac{5,6}{22,4}=0,25mol\\ n_{Al}=a;n_{Fe}=b\\ \left\{{}\begin{matrix}3a+b=0,25\\27a+56b=8,3\end{matrix}\right.\\ a=\dfrac{19}{470};b=\dfrac{121}{940}\\ \%m_{Al}=\dfrac{\dfrac{19}{470}\cdot27}{8,3}\cdot100=13,15\%\\ \%m_{Fe}=100-13,15=86,85\%\\ c)n_{HCl}=3\cdot\dfrac{19}{470}+2\cdot\dfrac{121}{940}=\dfrac{89}{235}mol\\ m_{ddHCl=}=\dfrac{\dfrac{89}{235}\cdot36,5}{7,3}\cdot100=189g\\ d)n_{AlCl_3}=n_{Al}=\dfrac{19}{470}mol\\ n_{Fe}=n_{FeCl_2}=\dfrac{121}{940}mol\)
\(m_{dd}=8,3+189-0,25.2=196,8g\\ C_{\%AlCl_3}=\dfrac{\dfrac{19}{470}\cdot133,8}{196,8}\cdot100=2,8\%\\ C_{\%FeCl_2}=\dfrac{\dfrac{121}{940}127}{196,8}\cdot100=8,3\%\)
n H2 = 13,44/22,4 = 0,6(mol)
$2Al + 6HCl \to 2AlCl_3 + 3H_2$
n Al = 2/3 n H2 = 0,4(mol)
%m Al = 0,4.27/21 .100% = 51,43%
%m Al2O3 = 100% -51,43% = 48,57%
b)
=> n Al2O3 = (21 - 0,4.27)/102 = 0,1(mol)
$Al_2O_3 + 6HCl \to 2AlCl_3 + 3H_2O$
n HCl = 3n Al + 6n HCl = 0,4.3 + 0,1.6 = 1,8(mol)
=> m dd HCl = 1,8.36,5/20% = 328,5(gam)
=> V dd HCl = m/D = 328,5/1,18 = 278,39(ml)
\(n_{H2}=\dfrac{1,12}{22,4}=0,05\left(mol\right)\)
Pt : \(Mg+2HCl\rightarrow MgCl_2+H_2|\)
1 2 1 1
0,05 0,1 0,05 0,05
\(MgO+2HCl\rightarrow MgCl_2+H_2O|\)
1 2 1 1
0,2 0,4 0,2
a) \(n_{Mg}=\dfrac{0,05.1}{1}=0,05\left(mol\right)\)
\(m_{Mg}=0,05.24=1,2\left(g\right)\)
\(m_{MgO}=9,2-1,2=8\left(g\right)\)
0/0Mg = \(\dfrac{1,2.100}{9,2}=13,04\)0/0
0/0MgO = \(\dfrac{8.100}{9,2}=86,96\)0/0
b) Có : \(m_{MgO}=8\left(g\right)\)
\(n_{MgO}=\dfrac{8}{40}=0,2\left(mol\right)\)
\(n_{HCl\left(tổng\right)}=0,1+0,4=0,5\left(mol\right)\)
\(m_{HCl}=0,5.36,5=18,25\left(g\right)\)
\(m_{ddHCl}=\dfrac{18,25.100}{14,6}=125\left(g\right)\)
c) \(n_{MgCl2\left(tổng\right)}=0,05+0,2=0,25\left(mol\right)\)
⇒ \(m_{MgCl2}=0,25.95=23,75\left(g\right)\)
\(m_{ddspu}=9,2+125-\left(0,05.2\right)=134,1\left(g\right)\)
\(C_{MgCl2}=\dfrac{23,75.100}{134,1}=17,71\)0/0
Chúc bạn học tốt
a)\(n_{H_2}=\dfrac{1,12}{22,4}=0,05\left(mol\right)\)
PTHH: Mg + 2HCl → MgCl2 + H2
Mol: 0,05 0,1 0,05 0,05
PTHH: MgO + 2HCl → MgCl2 + H2O
Mol: 0,2 0,4 0,2
\(\%m_{Mg}=\dfrac{0,05.24.100\%}{9,2}=13,04\%;\%m_{MgO}=100-13,04=86,96\%\)
\(n_{MgO}=\dfrac{9,2-0,05.24}{40}=0,2\left(mol\right)\)
b,\(m_{HCl}=\left(0,1+0,4\right).36,5=18,25\left(g\right)\)
\(m_{ddHCl}=\dfrac{18,25.100}{14,6}=125\left(g\right)\)
c,mdd sau pứ = 9,2+125-0,05.2 = 134,1 (g)
\(C\%_{ddMgCl_2}=\dfrac{\left(0,05+0,2\right).95.100\%}{134,1}=17,71\%\)
Tham khảo
a, PT: \(2Al+6HCl\rightarrow2AlCl_3+3H_2\)
\(Al_2O_3+6HCl\rightarrow2AlCl_3+3H_2O\)
Ta có: \(n_{H_2}=\dfrac{3,36}{22,4}=0,15\left(mol\right)\)
Theo PT: \(n_{Al}=\dfrac{2}{3}n_{H_2}=0,1\left(mol\right)\)
\(\Rightarrow\left\{{}\begin{matrix}\%m_{Al}=\dfrac{0,1.27}{5,25}.100\%\approx51,43\%\\\%m_{Al_2O_3}\approx48,57\%\end{matrix}\right.\)
b, \(n_{Al_2O_3}=\dfrac{5,25-0,1.27}{102}=0,025\left(mol\right)\)
Theo PT: \(n_{HCl}=3n_{Al}+6n_{Al_2O_3}=0,45\left(mol\right)\)
\(\Rightarrow m_{ddHCl}=\dfrac{0,45.36,5}{29,2\%}=56,25\left(g\right)\)
c, \(n_{H_2SO_4}=\dfrac{1}{2}n_{HCl}=0,225\left(mol\right)\)
\(\Rightarrow m_{ddH_2SO_4}=\dfrac{0,225.98}{19,6\%}=112,5\left(g\right)\)
nH2 = \(\dfrac{4,48}{22,4}\) = 0,2 (mol)
Zn + 2HCl ----> ZnCl2 + H2 (1)
ZnO + 2HCl ----> ZnCl2 + H2O (2)
nZn = nZnCl2 (1) = nH2 = 0,2 (mol)
=> mZn = 0.2 x 65 = 13 (g)
=> mZnO = 21,1 - 13 = 8,1 (g)
=> nZnO = 8,1/81 = 0.1 (mol)
nZnCl2 (2) = nZnO = 0.1 (mol)
C%ZnCl2 = \(\dfrac{152\left(0,2+0,1\right)}{21,1+200}\times100\%=20.62\%\)
a, \(\overline{M_A}=\dfrac{M_{O_2}.V_{O_2}+M_{N_2}.V_{N_2}}{V_{O_2}+V_{N_2}}\)
Mà VN2 = VO2.
\(\Rightarrow\overline{M_A}=....................\)
tháy rối tính thui đoạn sau thì ai cx b r nhỉ.
b, áp dụn ct tb khác thui
a, \(\overline{M_A}=\dfrac{M_{O_2}.n_{O_2}+M_{N_2}.n_{N_2}}{n_{O_2}+n_{N_2}}\)
Thay \(n=\dfrac{m}{M}\)
rút gọn rồi tính đc
nH2=13.44/22.4=0.6 mol
a)2Al + 6HCl ---> 2AlCl3 + 3H2
0.4.......1.2......................... 0.6
Al2O3 + 6HCl -----> 2AlCl3 + 3H2O
0.1............0.6
b)mAl=0.4*27=10.8g
=> %Al=10.8*100/21=51.43%
=>%Al2O3=100-51.43=48.57%
c)nHCl=1.2+0.6=1.8 mol
=>mHCl= 1.8*36.5=65.7g
=>mdd HCl= 65.7*100/7.3=900g
VHCl = m/D= 900/1.03= 873.9 lít.
Em bị nhầm đơn vị của dung dịch axit ở dòng cuối rồi