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\(200ml=0,2l\\ n_{Na_2CO_3}=0,5.0,2=0,1\left(mol\right)\\ PTHH:Na_2CO_3+2HCl\rightarrow2NaCl+CO_2\uparrow+H_2O\\ \left(mol\right)........0,1\rightarrow...0,2.......0,2..........0,1.........0,1\\ a,C_{M_{HCl}}=\dfrac{0,2}{0,2}=1\left(M\right)\\ b,m_{NaCl}=0,2.58,5=11,7\left(g\right)\\c, V_{ddNaCl}=V_{ddNa_2CO_3}+V_{ddHCl}=0,2+0,2=0,4\left(l\right)\\ C_{M_{NaCl}}=\dfrac{0,2}{0,4}=0,5\left(M\right)\)
vì em trộn 2 dung dịch lại với nhau mà, ví dụ em đổ 1 chai nước 500ml vào 1 chai nước 500 ml thì mình phải được 1 lít nước chứ
Bài 1
\(a,n_{CuO}=\dfrac{16}{80}=0,2\left(mol\right)\\ CuO+2HCl\xrightarrow[]{}CuCl_2+H_2O\\ n_{CuCl_2}=n_{CuO}=0,2mol\\ m_{CuCl_2}=0,2.135=27\left(g\right)\\ b.n_{HCl}=0,2.2=0,4\left(mol\right)\\ C_{MHCl}=\dfrac{0,4}{0,5}=0,8\left(M\right)\)
Bài 5
\(a,n_{NaOH}=0,2.1=0,2\left(mol\right)\\ 2NaOH+H_2SO_4\xrightarrow[]{}Na_2SO_4+2H_2O\\ n_{H_2SO_4}=0,2:2=0,1\left(mol\right)\\ C_{MH_2SO_4}=\dfrac{0,1}{0,4}=0,25\left(M\right)\\ b,n_{Na_2SO_4}=0,2:2=0,1\left(mol\right)\\ C_{MNa_2SO_4}=\dfrac{0,1}{0,2+0,4}=\dfrac{1}{6}\left(M\right)\\ c,m_{Na_2SO_4}=0,1.142=14,2\left(g\right)\)
Ta có: \(n_{NaOH}=0,1.0,5=0,05\left(mol\right)\)
PT: \(CH_3COOH+NaOH\rightarrow CH_3COONa+H_2O\)
Theo PT: \(n_{CH_3COOH}=n_{CH_3COONa}=n_{NaOH}=0,05\left(mol\right)\)
a, \(C_{M_{CH_3COOH}}=\dfrac{0,05}{0,2}=0,25\left(M\right)\)
b, \(m_{CH_3COONa}=0,05.82=4,1\left(g\right)\)
a)
$Fe + CuSO_4 \to FeSO_4 + Cu$
Theo PTHH : $n_{Cu} = n_{CuSO_4} = 0,3.1 = 0,3(mol)$
$m_{Cu} = 0,3.64 = 19,2(gam)$
b) $n_{FeSO_4} = n_{CuSO_4} = 0,3(mol)$
$\Rightarrow m_{FeSO_4} = 0,3.152 = 45,6(gam)$
c) $FeSO_4 + 2NaOH \to Fe(OH)_2 + Na_2SO_4$
$n_{Fe(OH)_2} = n_{FeSO_4} = 0,3(mol)$
$m_{Fe(OH)_2} = 0,3.90 = 27(gam)$
PTHH: \(K_2O+2HCl\rightarrow2KCl+H_2O\)
\(K_2SO_3+2HCl\rightarrow2KCl+SO_2\uparrow+H_2O\)
a) Ta có: \(\left\{{}\begin{matrix}n_{HCl}=\dfrac{200\cdot14,6\%}{36,5}=0,8\left(mol\right)\\n_{SO_2}=\dfrac{6,72}{22,4}=0,3\left(mol\right)\end{matrix}\right.\) \(\Rightarrow\left\{{}\begin{matrix}n_{K_2SO_3}=0,3\left(mol\right)\\n_{K_2O}=0,1\left(mol\right)\end{matrix}\right.\)
\(\Rightarrow\left\{{}\begin{matrix}\%m_{K_2O}=\dfrac{0,1\cdot94}{0,1\cdot94+0,3\cdot158}\cdot100\%\approx16,55\%\\\%m_{K_2SO_3}=83,45\%\end{matrix}\right.\)
b) Theo các PTHH: \(n_{KCl}=0,8\left(mol\right)\) \(\Rightarrow m_{KCl}=74,5\cdot0,8=59,6\left(g\right)\)
Mặt khác: \(\left\{{}\begin{matrix}m_{hh}=56,8\left(g\right)\\m_{SO_2}=0,3\cdot64=19,2\left(g\right)\end{matrix}\right.\)
\(\Rightarrow m_{dd}=m_{hh}+m_{ddHCl}-m_{SO_2}=237,6\left(g\right)\)
\(\Rightarrow C\%_{KCl}=\dfrac{59,6}{237,6}\cdot100\%\approx25,1\%\)
a, Ta có
CuO + 2HCl \(\rightarrow\) CuCl2 + H2O
x \(\rightarrow\) 2x \(\rightarrow\) x \(\rightarrow\) x
Fe2O3 + 6HCl \(\rightarrow\) 2FeCl3 + 3H2O
y \(\rightarrow\) 6y \(\rightarrow\) 2y \(\rightarrow\) 3y
Theo 2 phương trình trên ta có
nCuCl2 / nFeCl3 = 1/1 => x / 2y = 1/1
=> x = 2y => x - 2y = 0
=> \(\left\{{}\begin{matrix}80x+160y=8\\\text{x - 2y = 0}\end{matrix}\right.\)
=> \(\left\{{}\begin{matrix}x=0,05\\y=0,025\end{matrix}\right.\)
=> MHCl = ( 2x + 6y ) . 36,5 = 9,125 ( gam )
b, 200 ml = 0,2 l
=> CM HCl = n : V = ( 2x + 6y ) : 0,2 = 1,25 M
\(n_{CuO}=\dfrac{8}{80}=0,1\left(mol\right)\)
a) Pt : \(CuO+2HCl\rightarrow CuCl_2+H_2O|\)
1 2 1 1
0,1 0,2 0,1
b) \(n_{HCl}=\dfrac{0,1.2}{1}=0,2\left(mol\right)\)
⇒ \(m_{HCl}=0,2.36,5=7,3\left(g\right)\)
\(C_{ddHCl}=\dfrac{7,3.100}{200}=3,65\)0/0
c) \(n_{CuCl2}=\dfrac{0,2.1}{2}=0,1\left(mol\right)\)
⇒ \(m_{CuCl2}=0,1.135=13,5\left(g\right)\)
Chúc bạn học tốt
a) Khí A : Cacbon đioxit
b) $CaCO_3 + 2HCl \to CaCl_2 + CO_2 + H_2O$
$n_{CO_2} = \dfrac{448}{1000.22,4} = 0,02(mol)$
Theo PTHH : $n_{HCl} = 2n_{CO_2} = 0,04(mol)$
$C_{M_{HCl}} = \dfrac{0,04}{0,2} = 0,2M$
c) $n_{CaCO_3} = n_{CO_2} = 0,02(mol)$
$\%m_{CaCO_3} = \dfrac{0,02.100}{5}.100\% = 40\%$
$\%m_{CaSO_4} = 100\% - 40\% = 60\%$
\(CaO+2HCl\rightarrow CaCl_2+H_2O\)
0,5 0,5
\(m_{CaCl_2}=0.5\cdot111=55.5\left(g\right)\)
0,5 thứ 2 nằm ở 2HCl hay CaCl2 v ạ