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Bài 1
\(a)n_{H_2}=\dfrac{3,36}{22,4}=0,15mol\\ Fe+2HCl\rightarrow FeCl_2+H_2\)
0,15 0,3 0,15 0,15
\(\%m_{Fe}=\dfrac{0,15.56}{12}\cdot100\%=70\%\\ \%m_{FeO}=100\%-70\%=30\%\\ b)n_{FeO}=\dfrac{12-0,15.56}{72}=0,05mol\\ FeO+2HCl\rightarrow FeCl_2+H_2O\)
0,05 0,1
\(V_{ddHCl}=\dfrac{0,1+0,3}{2}=0,2l\)
Bài 2
\(a)Na_2O+H_2O\rightarrow2NaOH\\ b)BaO+H_2O\rightarrow Ba\left(OH\right)_2\\ c)BaSO_4?\\ BaO+H_2O\rightarrow Ba\left(OH\right)_2\\ Ba\left(OH\right)_2+CuSO_4\rightarrow BaSO_4+Cu\left(OH\right)_2\\ d)Na_2O+H_2O\rightarrow2NaOH\\ 2NaOH+CuSO_4\rightarrow Cu\left(OH\right)_2+Na_2SO_4\\ e)Na_2O+H_2O\rightarrow2NaOH\\ 2NaOH+FeCl_2\rightarrow Fe\left(OH\right)_2+2NaCl\)
a. PTHH : Mg + 2HCl ➝ MgCl2 + H2 (1)
b. theo bài : nH2 = 3,36 : 22,4 = 0,15 (mol)
theo (1) nMg = nH2 = 0,15 (mol)
➞ mMg = 0,15 ✖ 24 = 3,6 (g)
➞ %mMg = (3,6 : 5)✖100 = 72%
➞ %mCu = 100% - 72% = 28%
c. theo (1) nHCl = 2nH2 = 2✖0,15 = 0,3 (mol)
mHCl = 0,3✖36,5 = 10,95(g)
➜mddHCl = (10,95✖100):14,6 = 75(g)
d. dung dịch Y : MgCl2
mdd(spư)= 3,6+75-0,3 = 78,3(g)
theo (1) nMgCl2 = nH2 = 0,15(mol)
mMgCl2 = 0,15✖95 = 14,25(g)
C%MgCl2 = (14,25 : 78,3)✖100 = 18,199%
*Sửa đề: "13,44 lít H2" và "24,9 gam hh 2 kim loại"
PTHH: \(2Al+6HCl\rightarrow2AlCl_3+3H_2\uparrow\)
a_____3a_____________\(\dfrac{3}{2}\)a (mol)
\(Zn+2HCl\rightarrow ZnCl_2+H_2\uparrow\)
b_____2b_____________b (mol)
Ta lập HPT: \(\left\{{}\begin{matrix}27a+65b=24,9\\\dfrac{3}{2}a+b=\dfrac{13,44}{22,4}=0,6\end{matrix}\right.\) \(\Rightarrow\left\{{}\begin{matrix}a=0,2\\b=0,3\end{matrix}\right.\)
\(\Rightarrow\left\{{}\begin{matrix}n_{Al}=0,2\left(mol\right)\\n_{Zn}=0,3\left(mol\right)\\n_{HCl}=1,2\left(mol\right)\end{matrix}\right.\) \(\Rightarrow\left\{{}\begin{matrix}m_{Al}=0,2\cdot27=5,4\left(g\right)\\m_{Zn}=19,5\left(g\right)\\m_{ddHCl}=\dfrac{1,2\cdot36,5}{7,3\%}=600\left(g\right)\end{matrix}\right.\)
a, \(n_{H_2}=\dfrac{6,72}{22,4}=0,3\left(mol\right)\)
mhh Zn và Fe = 21,6-3 = 18,6 (g)
PTHH: Zn + H2SO4 → ZnSO4 + H2
Mol: x x
PTHH: Fe + H2SO4 → FeSO4 + H2
Mol: y y
Ta có: \(\left\{{}\begin{matrix}65x+56y=18,6\\x+y=0,3\end{matrix}\right.\Leftrightarrow\left\{{}\begin{matrix}x=0,2\\y=0,1\end{matrix}\right.\)
\(\%m_{Zn}=\dfrac{0,2.65.100\%}{21,6}=60,19\%\)
\(\%m_{Fe}=\dfrac{0,1.56.100\%}{21,6}=25,93\%\)
\(\%m_{Cu}=100-60,19-25,93=13,88\%\)
b,
PTHH: Zn + H2SO4 → ZnSO4 + H2
Mol: 0,2 0,2 0,2
PTHH: Fe + H2SO4 → FeSO4 + H2
Mol: 0,1 0,1 0,1
\(m_{H_2SO_4}=\left(0,1+0,2\right).98=29,4\left(g\right)\Rightarrow m_{ddH_2SO_4}=\dfrac{29,4.100\%}{25\%}=117,6\left(g\right)\)
c,mdd sau pư = 21,6+117,6- (0,1+0,2).2 = 138,6 (g)
\(C\%_{ddZnSO_4}=\dfrac{0,2.161.100\%}{138,6}=23,23\%\)
\(C\%_{ddFeSO_4}=\dfrac{0,1.152.100\%}{138,6}=10,97\%\)
a)
\(n_{H_2}=\dfrac{2,24}{22,4}=0,1\left(mol\right)\)
PTHH: Mg + 2HCl --> MgCl2 + H2
_____0,1<---0,2<-------0,1<---0,1
=> mHCl = 0,2.36,5 = 7,3 (g)
=> \(m_{ddHCl}=\dfrac{7,3.100}{7,3}=100\left(g\right)\)
mdd sau pư = 0,1.24 + 100 - 0,1.2 = 102,2 (g)
\(C\%\left(MgCl_2\right)=\dfrac{0,1.95}{102,2}.100\%=9,2955\%\)
b)
CTHH: AaOb
PTHH: \(A_aO_b+2bHCl->aACl_{\dfrac{2b}{a}}+bH_2O\)
____________0,2------->\(\dfrac{0,1a}{b}\)
=> \(\dfrac{0,1a}{b}\left(M_A+35,5.\dfrac{2b}{a}\right)=13,5\)
=> \(M_A=\dfrac{64b}{a}=\dfrac{2b}{a}.32\)
Nếu \(\dfrac{2b}{a}=1\) => MA = 32 (L)
Nếu \(\dfrac{2b}{a}=2\) => MA = 64(Cu)
Mg+2HCl->MgCl2+H2
0,3---0,6--------------0,3 mol
Cu ko td với HCl
n H2=6,72\22,4=0,3 mol
=>m Mg=0,3.24=7,2g
=>m Cu=13,6-7,2=6,4g
=>VHCl=0,6\1=0,6l=600ml