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Bài 5
Fe + 2CH3COOH \(\rightarrow\) (CH3COO)2Fe + H2(1)
nCH3COOH = \(\dfrac{4,5}{60}=0,075mol\)
a) THeo pt: n(CH3COO)2Fe = \(\dfrac{1}{2}.nCH_3COOH=0,0375mol\)
=> m = 6,525g
c) Theo pt (1) nH2 = 1/2nCH3COOH = 0,0375 mol
2H2 + O2 \(\xrightarrow[]{t^o}\) 2H2O
Theo pt: nO2 = 0,5nH2 = 0,01875mol
=> VO2 = 0,42 lít
=> Vkk = 0,42.5 = 2,1 lít
a, Mg + 2HCl \(\rightarrow\) MgCl2 + H2 Cu + 2HCl \(\rightarrow\) CuCl2 + H2
b, \(\left\{{}\begin{matrix}n_{Mg}=x\\n_{Cu}=y\end{matrix}\right.\Rightarrow\left\{{}\begin{matrix}24x+64y=16\\x+y=\dfrac{2,24}{22,4}\end{matrix}\right.\Rightarrow\left\{{}\begin{matrix}x=-0,24\\y=0,34\end{matrix}\right.\)
Xem lại đầu bài nha
a) $n_{CaCO_3} = 0,15(mol)$
$CaCO_3 + 2HCl \to CaCl_2 + CO_2 + H_2O$
$n_{HCl} = 2n_{CaCO_3} = 0,3(mol)$
$m_{dd\ HCl} = \dfrac{0,3.36,5}{7,3\%} = 150(gam)$
b)
$n_{CaCl_2} = n_{CO_2} = n_{CaCO_3} =0,15(mol)$
$V_{CO_2} = 0,15.22,4 = 3,36(lít)$
c)
$m_{dd} = 15 + 150 - 0,15.44 = 158,4(gam)$
$C\%_{CaCl_2} = \dfrac{0,15.111}{158,4}.100\% = 10,51\%$
\(n_{CO_2}=\dfrac{2,8}{22,4}=0,125\left(mol\right)\)
PTHH :
\(CO_2+2KOH\rightarrow K_2CO_3+H_2O\)
0,125 0,25 0,125
\(a,C_{M\left(KOH\right)}=\dfrac{0,25}{0,1}=2,5\left(M\right)\)
\(b,C_{M\left(K_2CO_3\right)}=\dfrac{0,125}{0,1}=1,25\left(M\right)\)
\(n_{CH_3COOH}=\dfrac{300\cdot5\%}{60}=0.25\left(mol\right)\)
\(2CH_3COOH+Zn\rightarrow\left(CH_3COO\right)_2Zn+H_2\)
\(0.25........................................................0.125\)
\(V_{H_2}=0.125\cdot22.4=2.8\left(l\right)\)
\(n_{C_2H_5OH}=0.1\cdot2=0.2\left(mol\right)\)
\(CH_3COOH+C_2H_5OH⇌CH_3COOC_2H_5+H_2O\left(ĐK:H_2SO_{4\left(đ\right)},t^0\right)\)
\(0.2......................0.2.....................0.2\)
\(\Rightarrow CH_3COOHdư\)
\(m_{CH_3COOC_2H_5}=0.2\cdot88=17.6\left(g\right)\)
Ta có: \(n_{HCl}=\dfrac{200}{1000}.2=0,4\left(mol\right)\)
\(PTHH:Mg+2HCl--->MgCl_2+H_2\uparrow\left(1\right)\)
a. Theo PT(1): \(n_{Mg}=n_{H_2}=n_{MgCl_2}=\dfrac{1}{2}.n_{HCl}=\dfrac{1}{2}.0,4=0,2\left(mol\right)\)
\(\Rightarrow\left\{{}\begin{matrix}m_{Mg}=0,2.24=4,8\left(g\right)\\V_{H_2}=0,2.22,4=4,48\left(lít\right)\end{matrix}\right.\)
b. \(PTHH:2NaOH+MgCl_2--->Mg\left(OH\right)_2\downarrow+2NaCl\left(2\right)\)
Ta có: \(n_{NaOH}=\dfrac{\dfrac{20\%.100}{100\%}}{40}=0,5\left(mol\right)\)
Ta thấy: \(\dfrac{0,5}{2}>\dfrac{0,2}{1}\)
Vậy NaOH dư.
Theo PT(2): \(n_{Mg\left(OH\right)_2}=n_{MgCl_2}=0,2\left(mol\right)\)
\(\Rightarrow m_{Mg\left(OH\right)_2}=0,2.58=11,6\left(g\right)\)
a: \(Mg+2HCl\rightarrow MgCl_2+H_2\)
200ml=0,2 lít
\(n_{HCl}=0.2\cdot22.4=4.48\left(mol\right)\)
\(\Leftrightarrow n_{H_2}=2.24\left(mol\right)\)
\(\Leftrightarrow m_{H_2}=n_{H_2}\cdot M=2.24\cdot1=2.24\left(g\right)\)
\(n_{MgCl_2}=2.24\left(mol\right)\)
\(\Leftrightarrow n_{Mg}=2.24\left(mol\right)\)
\(\Leftrightarrow m_{Mg}=2.24\cdot24=53.76\left(g\right)\)
a, \(Mg+H_2SO_4\rightarrow MgSO_4+H_2\)
b, \(n_{Mg}=\dfrac{4,1}{24}=\dfrac{41}{240}\left(mol\right)\)
Theo PT: \(n_{H_2}=n_{MgSO_4}=n_{Mg}=\dfrac{41}{240}\left(mol\right)\)
\(\Rightarrow V_{H_2}=\dfrac{41}{240}.24,79\approx4,23\left(l\right)\)
c, \(m_{MgSO_4}=\dfrac{41}{240}.120=20,5\left(g\right)\)
\(n_{Mg}=\dfrac{4,1}{24}=\dfrac{41}{210}\left(mol\right)\)
PTHH :
\(Mg+H_2SO_4\rightarrow MgSO_4+H_2\uparrow\)
41/210 41/210 41/210
\(b,V_{H_2}=\dfrac{41}{240}.24,79=4,235\left(l\right)\)
\(c,m_{MgSO_4}=\dfrac{41}{240}.120=20,5\left(g\right)\)
a) n CH3COOH = 300.5%/60 = 0,25(mol)
Zn + 2CH3COOH $\to$ (CH3COO)2Zn + H2
Theo PTHH :
n H2 = 1/2 n CH3COOH = 0,25/2 = 0,125(mol)
V H2 = 0,125.22,4 = 2,8(lít)
b) n C2H5OH = 0,1.2 = 0,2(mol)
\(CH_3COOH + C_2H_5OH \buildrel{{H_2SO_4,t^o}}\over\rightleftharpoons CH_3COOC_2H_5 + H_2O\)
Ta thấy :
n CH3COOH = 0,25 > n C2H5OH = 0,2 => CH3COOH dư
n CH3COOC2H5 = n C2H5OH = 0,2 mol
=> m CH3COOC2H5 = 0,2.88 = 17,6 gam
Ta có: \(n_{H_2}=\dfrac{5,6}{22,4}=0,25\left(mol\right)\)
PT: \(2Al+3H_2SO_4\rightarrow Al_2\left(SO_4\right)_3+3H_2\)
a, \(n_{Al}=\dfrac{2}{3}n_{H_2}=\dfrac{1}{6}\left(mol\right)\Rightarrow m_{Al}=\dfrac{1}{6}.27=4,5\left(g\right)\)
b, \(n_{H_2SO_4}=n_{H_2}=0,25\left(mol\right)\Rightarrow C_{M_{H_2SO_4}}=\dfrac{0,25}{0,2}=1,25\left(M\right)\)
c, \(n_{Al_2\left(SO_4\right)_3}=\dfrac{1}{3}n_{H_2}=\dfrac{1}{12}\left(mol\right)\)
\(\Rightarrow m_{Al_2\left(SO_4\right)_3}=\dfrac{1}{12}.342=28,5\left(g\right)\)