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a)
$BaCl_2 + H_2SO_4 \to BaSO_4 + 2HCl$
$n_{BaCl_2} = 0,1 < n_{H_2SO_4} = 0,2$ nên $H_2SO_4$ dư
$n_{BaSO_4} = n_{BaCl_2} = 0,1(mol)$
$m_{BaSO_4} = 0,1.233 = 23,3(gam)$
b)
A gồm :
$HCl : 0,1.2 = 0,2(mol)$
$H_2SO_4\ dư : 0,2 - 0,1 = 0,1(mol)$
$V_{dd} = 0,1 + 0,1= 0,2(lít)$
$C_{M_{HCl}} = \dfrac{0,2}{0,2} = 1M$
$C_{M_{H_2SO_4}} = \dfrac{0,1}{0,2} = 0,5M$
c)
$2NaOH + H_2SO_4 \to Na_2SO_4 + 2H_2O$
$n_{NaOH} = 2n_{H_2SO_4\ dư} = 0,2(mol)$
$m_{dd\ NaOH} = \dfrac{0,2.40}{15\%} = 53,33(gam)$
$a\big)$
$n_{CH_3COOH}=\dfrac{100}{1000}.1=0,1(mol)$
$CH_3COOH+NaOH\to CH_3COONa+H_2O$
Theo PT: $n_{NaOH}=n_{CH_3COOH}=0,1(mol)$
$\to C\%_{NaOH}=\dfrac{0,1.40}{50}.100\%=80\%$
$b\big)$
$n_{Na_2CO_3}=\dfrac{10,6}{106}=0,1(mol)$
$2CH_3COOH+Na_2CO_3\to 2CH_3COONa+CO_2+H_2O$
Theo PT: $\begin{cases} n_{CO_2}=n_{Na_2CO_3}=0,1(mol)\\ n_{CH_3COONa}=2n_{Na_2CO_3}=0,2(mol) \end{cases}$
$\to C\%_{CH_3COONa}=\dfrac{0,2.82}{60+10,6-0,1.44}.100\%\approx 24,77\%$
a) \(\left\{{}\begin{matrix}n_{CuSO_4}=0,3.1=0,3\left(mol\right)\\n_{BaCl_2}=0,1.2=0,2\left(mol\right)\end{matrix}\right.\)
PTHH: \(CuSO_4+BaCl_2\rightarrow BaSO_4\downarrow+CuCl_2\)
Ban đầu: 0,3 0,2
Sau pư: 0,1 0 0,2 0,2
=> \(m_{kt}=m_{BaSO_4}=0,2.233=46,6\left(g\right)\)
b) \(CuSO_4+2NaOH\rightarrow Cu\left(OH\right)_2\downarrow+Na_2SO_4\)
0,1-------->0,2
\(CuCl_2+2NaOH\rightarrow Cu\left(OH\right)_2\downarrow+2NaCl\)
0,2------>0,4
=> \(m_{ddNaOH}=\dfrac{\left(0,2+0,4\right).40}{15\%}=160\left(g\right)\)
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
\(a,n_{NaOH}=0,2.1=0,2\left(mol\right)\\ 2NaOH+H_2SO_4\xrightarrow[]{}Na_2SO_4+2H_2O\\ n_{H_2SO_4}=0,2:2=0,1\left(mol\right)\\ C_{MH_2SO_4}=\dfrac{0,1}{0,4}=0,25\left(M\right)\\ b,n_{Na_2SO_4}=0,2:2=0,1\left(mol\right)\\ C_{MNa_2SO_4}=\dfrac{0,1}{0,2+0,4}=\dfrac{1}{6}\left(M\right)\\ c,m_{Na_2SO_4}=0,1.142=14,2\left(g\right)\)
\(n_{Fe_2O_3}=\dfrac{16}{160}=0,1\left(mol\right)\)
PT: \(Fe_2O_3+6HCl\rightarrow2FeCl_3+3H_2O\)
a, \(n_{HCl}=6n_{Fe_2O_3}=0,6\left(mol\right)\)
\(\Rightarrow C\%_{HCl}=\dfrac{0,6.36,5}{500}.100\%=4,38\%\)
b, \(n_{FeCl_3}=2n_{Fe_2O_3}=0,2\left(mol\right)\)
PT: \(FeCl_3+3KOH\rightarrow3KCl+Fe\left(OH\right)_{3\downarrow}\)
______0,2_______0,6______________0,2 (mol)
\(\Rightarrow C_{M_{KOH}}=\dfrac{0,6}{0,2}=3\left(M\right)\)
\(m_{Fe\left(OH\right)_3}=0,2.107=21,4\left(g\right)\)
Bài 10:
PTHH: \(Na_2CO_3+BaCl_2\rightarrow2NaCl+BaCO_3\downarrow\)
a) Ta có: \(n_{Na_2CO_3}=\dfrac{200\cdot10,6\%}{106}=0,2\left(mol\right)=n_{BaCO_3}\)
\(\Rightarrow m_{BaCO_3}=0,2\cdot197=39,4\left(g\right)\)
b) Theo PTHH: \(n_{BaCl_2}=n_{BaCO_3}=0,2mol\)
\(\Rightarrow C\%_{BaCl_2}=\dfrac{0,2\cdot208}{120}\cdot100\%\approx34,67\%\)
c) Theo PTHH: \(n_{NaCl}=2n_{BaCl_2}=0,4mol\) \(\Rightarrow m_{NaCl}=0,4\cdot58,5=23,4\left(g\right)\)
Mặt khác: \(m_{dd}=m_{ddNa_2CO_3}+m_{ddBaCl_2}-m_{BaCO_3}=280,6\left(g\right)\)
\(\Rightarrow C\%_{NaCl}=\dfrac{23,4}{280,6}\cdot100\%\approx8,34\%\)
\(n_{NaOH}=1\cdot0,05=0,05\left(mol\right)\\ PTHH:NaOH+HCl\rightarrow NaCl+H_2O\\ \Rightarrow n_{HCl}=n_{NaOH}=0,05\left(mol\right)\\ \Rightarrow C_{M_{HCl}}=\dfrac{0,05}{0,2}=0,25M\)
Vậy chọn B
\(a,2NaOH+MgSO_4\rightarrow Mg\left(OH\right)_2+Na_2SO_4\\ n_{NaOH}=0,5.1=0,5\left(mol\right)\\ b,n_{Mg\left(OH\right)_2}=\dfrac{0,5}{2}=0,25\left(mol\right)=n_{Na_2SO_4}\\ m_{kt}=m_{Mg\left(OH\right)_2}=58.0,25=14,5\left(g\right)\\ c,V_{ddX}=V_{ddNaOH}+V_{ddMgSO_4}=0,5+0,5=1\left(l\right)\\ C_{MddNa_2SO_4}=\dfrac{0,25}{1}=0,25\left(M\right)\)