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CaO+H2O\(\rightarrow\)Ca(OH)2
\(m_{CuO}=3,2gam\rightarrow m_{CaO}=20-3,2=16,8gam\)
\(n_{CaO}=\dfrac{16,8}{56}=0,3mol\)
\(n_{Ca\left(OH\right)_2}=n_{CaO}=0,3mol\)
\(C_{M_{Ca\left(OH\right)_2}}=\dfrac{0,3}{0,2}=1,5M\)
CuO + 2HCl -> CuCl2 + H2O (1)
Fe2O3 + 6HCl -> 2FeCl3 + 3H2O (2)
nHCl=0,2.3,5=0,7(mol)
Đặt nCuO=a
nFe2O3=b
Ta có hệ:
80a+160b=20
2a+6b=0,7
=>a=0,05;b=0,1
mCuO=80.0,05=4(g)
mFe2O3=20-4=16(g)
Theo PTHH 1 và 2 ta có:
nCuCl2=nCuO=0,05(mol)
nFeCl3=2nFe2O3=0,2(mol)
mCuCl2=135.0,05=6,75(g)
mFeCl3=162,5.0,2=32,5(g)
mdd =20+200.1,1=240(g)
C% dd CuCl2=6,72\240 .100%=2,8125%
C% dd FeCl3= 32,5\240 .100%=13,54%
nếu bn đoạn trên bn hiểu rồi thì thôi nhe
Ta có: \(\left\{{}\begin{matrix}80x+81y=12,1\\2x+2y=0,3\end{matrix}\right.\Leftrightarrow\left\{{}\begin{matrix}80x+81y=12,1\\80x+80y=12\end{matrix}\right.\Leftrightarrow\left\{{}\begin{matrix}y=0,1\\2x+2y=0,3\end{matrix}\right.\Leftrightarrow\left\{{}\begin{matrix}y=0,1\\x=0,05\end{matrix}\right.\)
Giống như giải hệ phương trình thôi bn
a,\(n_{HCl}=0,1.3=0,3\left(mol\right)\)
PTHH: CuO + 2HCl → CuCl2 + H2O
Mol: x 2x
PTHH: ZnO + 2HCl → ZnCl2 + H2O
Mol: y 2y
Ta có: \(\left\{{}\begin{matrix}80x+81y=12,1\\2x+2y=0,3\end{matrix}\right.\Leftrightarrow\left\{{}\begin{matrix}x=0,05\\y=0,1\end{matrix}\right.\)
\(m_{CuO}=0,05.80=4\left(g\right);m_{ZnO}=12,1-4=8,1\left(g\right)\)
c,
PTHH: CuO + H2SO4 → CuSO4 + H2O
Mol: 0,05 0,05
PTHH: ZnO + H2SO4 → ZnSO4 + H2O
Mol: 0,1 0,1
\(m_{ddH_2SO_4}=\dfrac{\left(0,05+0,1\right).98.100}{20}=73,5\left(g\right)\)
\(n_{CaO}=\dfrac{6.72}{56}=0.12\left(mol\right)\)
\(CaO+H_2O\rightarrow Ca\left(OH\right)_2\)
\(0.12..........................0.12\)
\(m_{Ca\left(OH\right)_2}=0.12\cdot74=8.88\left(g\right)\)
\(C_{M_{Ca\left(OH\right)_2}}=\dfrac{0.12}{0.2}=0.6\left(M\right)\)
PTHH: \(CaO+H_2O\rightarrow Ca\left(OH\right)_2\)
Ta có: \(n_{CaO}=\dfrac{6,72}{56}=0,12\left(mol\right)=n_{Ca\left(OH\right)_2}\)
\(\Rightarrow\left\{{}\begin{matrix}m_{Ca\left(OH\right)_2}=0,12\cdot74=8,88\left(g\right)\\C_{M_{Ca\left(OH\right)_2}}=\dfrac{0,12}{0,2}=0,6\left(M\right)\end{matrix}\right.\)
\(a)n_{HCl}=0,2.1,5=0,3mol\\ CaO+2HCl\rightarrow CaCl_2+H_2O\\ CuO+2HCl\rightarrow CuCl_2+H_2O\\ \Rightarrow\left\{{}\begin{matrix}2n_{CaO}+2n_{CuO}=0,3\\56n_{CaO}+80n_{CuO}=10,8\end{matrix}\right.\\ \Rightarrow n_{CaO}=n_{CaCl_2}=0,05mol;n_{CuO}=n_{CuCl_2}=0,1mol\\ \%m_{CaO}=\dfrac{0,05.56}{10,8}\cdot100=25,93\%\\ \%m_{CuO}=100-25,93=74,07\%\\ b)C_{M_{CaCl_2}}=\dfrac{0,05}{0,2}=0,25M\\ C_{M_{CuCl_2}}=\dfrac{0,1}{0,2}=0,5M\)
\(CaO+2HCl\rightarrow CaCl_2+H_2O\)
x 2x x x
\(CuO+2HCl\rightarrow CuCl_2+H_2O\)
y 2y y y
\(\left\{{}\begin{matrix}56x+80y=10,8\\2x+2y=0,2.1,5=0,3\end{matrix}\right.\)
\(\Rightarrow x=0,05;y=0,1\)
\(a,\%m_{CaO}=0,05.56:10,8.100\%=25,93\left(\%\right)\)
\(\%m_{CuO}=100\%-25,93\%=74,07\%\)
\(b,C_{M\left(CaCl_2\right)}=\dfrac{0,05}{0,2}=0,25\left(M\right)\)
\(C_{M\left(CuCl_2\right)}=\dfrac{0,1}{0,2}=0,5\left(M\right)\)
$a)PTHH:2Al+6HCl\to 2AlCl_3+3H_2$
$n_{H_2}=\dfrac{5,04}{22,4}=0,225(mol)$
$\Rightarrow n_{Al}=0,15(mol)$
$\Rightarrow \%m_{Al}=\dfrac{0,15.27}{9,45}.100\%\approx 42,86\%$
$\Rightarrow \%m_{Cu}=100-42,86=57,14\%$
$b)$ Theo PT: $n_{HCl}=2n_{H_2}=0,45(mol)$
$\Rightarrow C_{M_{HCl}}=\dfrac{0,45.110\%}{0,5}=0,99M$
