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Ta có: \(n_{CuO}=\dfrac{16}{80}=0,2\left(mol\right)\)
PT: \(CuO+2HCl\rightarrow CuCl_2+H_2O\)
______0,2_____0,4_____0,2 (mol)
a, \(m_{CuCl_2}=0,2.135=27\left(g\right)\)
b, \(m_{HCl}=0,4.36,5=14,6\left(g\right)\Rightarrow C\%_{HCl}=\dfrac{14,6}{300}.100\%\approx4,867\%\)
c, Ta có: m dd sau pư = 16 + 300 = 316 (g)
\(\Rightarrow C\%_{CuCl_2}=\dfrac{27}{316}.100\%\approx8,54\%\)
Cho Ba(OH)2 vào muối Al sẽ có 2TH sau:
TH1: kết tủa Al(OH)3 chưa bị hòa tan
Al3+ + 3OH– → Al(OH)3↓
→ nAl(OH)3 = nAl3+ → nAl(OH)3 = xn + 0,04n
TH2: kết tủa Al(OH)3 bị hòa tan một phần
Al3+ + 3OH– → Al(OH)3↓
(xn + 0,04n)→ 3(xn + 0,04n) (xn + 0,04n)
Al(OH)3 + OH– → AlO2– + 2H2O
0,952 – 3(xn + 0,04n) ←0,952
→ nAl(OH)3 = 4xn + 0,16n – 0,952
a)
$2K + 2H_2O \to 2KOH + H_2$
$BaO + H_2O \to Ba(OH)_2$
Theo PTHH :
$n_K = 2n_{H_2} = 0,2(mol)$
$\%m_K = \dfrac{0,2.39}{23,1}.100\% = 33,77\%$
$\%m_{BaO} = 100\%- 33,77\% = 66,23\%$
b)
$n_{BaO} = \dfrac{23,1 - 0,2.39}{153} = 0,1(mol)$
$m_{dd} = 23,1 + 177,1 - 0,1.2 = 200(gam)$
$C\%_{KOH} = \dfrac{0,2.56}{200}.100\% = 5,6\%$
$C\%_{Ba(OH)_2} = \dfrac{0,1.171}{200}.100\% = 8,55\%$
c)
$KOH + HCl \to KCl + H_2O$
$Ba(OH)_2 + 2HCl \to BaCl_2 + 2H_2O$
$n_{HCl} = 2n_{Ba(OH)_2} + n_{KOH} = 0,4(mol)$
$V = \dfrac{0,4}{0,5} = 0,8(lít) = 800(ml)$
BTKL: mD + mNaHCO3 = mCO2 + mE
mD + 179,88 = 44.0,2 + 492 => mD = 320,92
BTKL: mMg + mddHCl = mH2 + mD
=> 24 . 0,4 + mddHCl = 2 . 0,4 + 320,92 => mddHCl = 312,12
=> C%HCl = 11,69%
PTHH: \(MgO+2HCl\rightarrow MgCl_2+H_2O\)
a_____2a_______a_______a (mol)
\(Al_2O_3+6HCl\rightarrow2AlCl_3+3H_2O\)
b_____6b_______2b_______3b (mol)
Ta lập HPT: \(\left\{{}\begin{matrix}40a+102b=18,2\\2a+6b=\dfrac{182,5\cdot20\%}{36,5}=1\end{matrix}\right.\) \(\Leftrightarrow\left\{{}\begin{matrix}a=0,2\\b=0,1\end{matrix}\right.\)
\(\Rightarrow\left\{{}\begin{matrix}\%m_{MgO}=\dfrac{0,2\cdot40}{18,2}\cdot100\%\approx43,96\%\\\%m_{Al_2O_3}=56,04\%\end{matrix}\right.\)
Theo PTHH: \(n_{MgCl_2}=0,2\left(mol\right)=n_{AlCl_3}\) \(\Rightarrow\left\{{}\begin{matrix}m_{MgCl_2}=0,2\cdot95=19\left(g\right)\\m_{AlCl_3}=0,2\cdot133,5=26,7\left(g\right)\end{matrix}\right.\)
\(\Rightarrow\left\{{}\begin{matrix}C\%_{MgCl_2}=\dfrac{19}{18,2+182,5}\cdot100\%\approx9,47\%\\C\%_{AlCl_3}=\dfrac{26,7}{182,5+18,2}\cdot100\%\approx13,3\%\end{matrix}\right.\)
a) mHCl=182,5. 20%=36,5(g) -> nHCl=1(mol)
Đặt nMgO=a(mol); nAl2O3=b(mol)
PTHH: MgO +2 HCl -> MgCl2 + H2O
a__________2a______a(mol)
Al2O3 + 6 HCl -> 2 AlCl3 + 3 H2O
b_______6b______2b(mol)
b) Ta có hpt:
\(\left\{{}\begin{matrix}40a+102b=18,2\\2a+6b=1\end{matrix}\right.\Leftrightarrow\left\{{}\begin{matrix}a=0,2\\b=0,1\end{matrix}\right.\)
=> mMgO=0,2.40=8(g)
=>%mMgO=(8/18,2).100=43,956%
=> %mAl2O3= 56,044%
c) m(muối)= mAlCl3 + mMgCl2= 133,5.2b+ 95.a= 133,5.0,1.2+95.0,2= 45,7(g)
d) mAlCl3= 26,7(g) ; mMgCl2 = 19(g)
mddsau= 18,2+ 182,5= 200,7(g)
=>C%ddAlCl3=(26,7/200,7).100=13,303%
C%ddMgCl2=(19/200,7).100=9,467%
a, Dung dịch K chứa CuCl2 → có màu xanh lá cây.
b, Ta có: \(m_{ddHCl}=1,1.100=110\left(g\right)\Rightarrow m_{HCl}=110.20,4\%=22,44\left(g\right)\)
\(\Rightarrow n_{HCl}=\dfrac{22,44}{36,5}\approx0,6\left(mol\right)\)
PT: \(CuO+2HCl\rightarrow CuCl_2+H_2O\)
____0,3_____0,6_____0,3 (mol)
⇒ x = mCuO = 0,3.80 = 24 (g)
c, Ta có: m dd sau pư = 24 + 110 = 134 (g)
\(\Rightarrow C\%_{CuCl_2}=\dfrac{0,3.135}{134}.100\%\approx30,22\%\)
d, Có: nCuCl2.2H2O = nCuCl2 = 0,3 (mol)
mCuCl2.2H2O = 0,3.171 = 51,3 (g)
\(\Rightarrow\%m_{H_2O\left(trongL\right)}=\dfrac{0,3.2.18}{51,3}.100\%\approx21,05\%\)
Bạn tham khảo nhé!