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a)
$Fe + H_2SO_4 \to FeSO_4 + H_2$
$n_{H_2SO_4} = n_{H_2} = n_{Fe} = \dfrac{16,8}{56} = 0,3(mol)$
$V = 0,3.22,4 = 6,72(lít)$
$C_{M_{H_2SO_4}} = \dfrac{0,3}{0,25} = 1,2M$
b)
$n_{CuO} = \dfrac{16}{80} = 0,2(mol)$
$CuO + H_2 \xrightarrow{t^o} Cu + H_2O$
$n_{CuO} < n_{H_2}$ nên $H_2$ dư
$n_{Cu} = n_{CuO} = 0,2(mol)$
$m_{Cu} = 0,2.64 = 12,8(gam)$
\(n_{Fe}=\dfrac{m}{M}=\dfrac{16,8}{56}=0,3\left(mol\right)\\ PT:Fe+H_2SO_4\rightarrow FeSO_4+H_2\)
0,3 0,3 0,3 (mol)
a) V= n. 22,4 = 0,3 . 22,4 = 6,72(l)
\(C\%=\dfrac{m_{H_2SO_4}}{m_{dd}}.100\%=\dfrac{0,3.98}{200}.100\%=11,76\%\)
b) PT: \(H_2+CuO\underrightarrow{t^o}Cu+H_2O\)
0,3 0,3
=> mCu=n.M=0,3.64=19,2(g)
\(n_{H_2}=\dfrac{3,24}{24}=0,135(mol)\\ Fe+H_2SO_4\to FeSO_4+H_2\\ \Rightarrow n_{H_2SO_4}=n_{FeSO_4}=0,135(mol)\\ \Rightarrow \begin{cases} C_{M_{H_2SO_4}}=\dfrac{0,135}{0,2}=0,675M\\ C_{M_{FeSO_4}}=\dfrac{0,135}{0,2}=0,675M \end{cases}\)
\(n_{Fe}=\dfrac{5,6}{56}=0,1\left(mol\right)\)
Pt : \(Fe+H_2SO_4\rightarrow FeSO_4+H_2|\)
1 1 1 1
0,1 0,1 0,1
a) \(n_{H2SO4}=\dfrac{0,1.1}{1}=0,1\left(mol\right)\)
\(V_{ddH2SO4}=\dfrac{0,1}{2}=0,05\left(l\right)\)
b) \(n_{FeSO4}=\dfrac{0,1.1}{1}=0,1\left(mol\right)\)
\(C_{M_{FeSO4}}=\dfrac{0,1}{0,05}=2\left(M\right)\)
Chúc bạn học tốt
a) \(n_{Zn}=\dfrac{6,5}{65}=0,1\left(mol\right)\)
PTHH: Zn + H2SO4 ---> ZnSO4 + H2
0,1--->0,1------->0,1------>0,1
=> \(V_{H_2}=0,1.22,4=2,24\left(l\right)\)
b) \(m_{\text{dd}H_2SO_4}=\dfrac{0,1.98}{19,6\%}=50\left(g\right)\)
=> \(m_{\text{dd}.sau.p\text{ư}}=50+6,5-0,1.2=56,3\left(g\right)\)
=> \(C\%_{ZnSO_4}=\dfrac{0,1.161}{56,3}.100\%=28,6\%\)
b,\(n_{HCl}=0,2.2=0,4\left(mol\right)\)
PTHH: CuO + 2HCl → CuCl2 + H2
Mol: 0,2 0,4
\(\Rightarrow m_{CuO}=0,2.80=16\left(g\right)\)
c,\(n_{ZnO}=\dfrac{16,2}{81}=0,2\left(mol\right)\)
PTHH: ZnO + H2SO4 → ZnSO4 + H2
Mol: 0,2 0,2
\(\Rightarrow V_{ddH_2SO_4}=\dfrac{0,2}{2}=0,1\left(l\right)\)
d,\(n_{H_2SO_4}=2.0,1=0,2\left(mol\right)\)
PTHH: H2SO4 + 2KOH → K2SO4 + 2H2O
Mol: 0,2 0,4
\(\Rightarrow V_{ddKOH}=\dfrac{0,4}{1}=0,4\left(l\right)\)
a)
$n_{Al} = 0,3(mol)$
$2Al + 3H_2SO_4 \to Al_2(SO_4)_3 + 3H_2$
Theo PTHH :
$n_{H_2SO_4} = \dfrac{3}{2}n_{Al} = 0,45(mol)$
$m_{dd\ H_2SO_4} = \dfrac{0,45.98}{12,25\%} = 360(gam)$
b)
$n_{H_2} = n_{H_2SO_4} = 0,45(mol)$
$V_{H_2} = 0,45.22,4 = 10,08(lít)$
c)
$n_{Al_2(SO_4)_3} = 0,15(mol)$
$m_{dd\ sau\ pư} = 8,1 + 360 - 0,45.2 = 367,2(gam)$
$C\%_{Al_2(SO_4)_3} = \dfrac{0,15.342}{367,2}.100\% = 14\%$
\(4.a/n_{Al}=\dfrac{5,4}{27}=0,2mol\\ 2Al+3H_2SO_4\rightarrow Al_2\left(SO_4\right)_3+3H_2\)
0,2 0,3 0,1 0,3
\(V_{H_2}=0,3.24,79=7,437l\\ b/C_{\%H_2SO_4}=\dfrac{0,3.98}{150}\cdot100=19,6\%\\ c/m_{Al_2\left(SO_4\right)_3}=0,1.342=34,2g\)
\(5.a/n_{MgO}=\dfrac{4}{40}=0,1mol\\ MgO+2HCl\rightarrow MgCl_2+H_2O\)
0,1 0,2 0,1 0,1
\(C_{\%HCl}=\dfrac{0,2.36,5}{200}\cdot100=3,65\%\\ b/C_{\%MgCl_2}=\dfrac{0,1.95}{200+4}\cdot100=4,66\%\\ c/NaOH+HCl\rightarrow NaCl+H_2O\\ n_{NaOH}=n_{HCl}=0,2mol\\ V_{NaOH}=\dfrac{0,2}{1}=0,2l=200ml\)
Mng giúp mik với mik đag cần gấp ạ
Fe+ H2SO4(loãng)→ FeSO4 + H2
(mol) 0,4 0,4
\(n_{Fe}=\dfrac{m}{M}=\dfrac{22,4}{56}=0,4\left(mol\right)\)
=> \(V_{H_2SO_4}=\dfrac{n}{C_M}=\dfrac{0,4}{2}=0,2\left(lít\right)\)
vậy thể tích của dung dịch H2SO4 là 0,2 lít. Chọn câu B