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Ta có: \(n_{C_2H_4}=\dfrac{11,2}{22,4}=0,5\left(mol\right)\)
PT: \(C_2H_4+3O_2\underrightarrow{t^o}2CO_2+2H_2O\)
a, \(n_{O_2}=3n_{C_2H_4}=1,5\left(mol\right)\Rightarrow V_{O_2}=1,5.22,4=33,6\left(l\right)\)
\(\Rightarrow V_{kk}=\dfrac{V_{O_2}}{20\%}=168\left(l\right)\)
b, \(n_{CO_2}=2n_{C_2H_4}=1\left(mol\right)\Rightarrow m_{CO_2}=1.44=44\left(g\right)\)
Sửa đề: "3,36 lít CO2"
Ta có: \(\left\{{}\begin{matrix}n_{NaOH}=\dfrac{18}{40}=0,45\left(mol\right)\\n_{CO_2}=\dfrac{3,36}{22,4}=0,15\left(mol\right)\end{matrix}\right.\) \(\Rightarrow\) Tạo muối trung hòa
PTHH: \(CO_2+2NaOH\rightarrow Na_2CO_3+H_2O\)
Bazơ dư nên tính theo CO2
Theo PTHH: \(n_{Na_2CO_3}=0,15\left(mol\right)=n_{NaOH\left(dư\right)}\) \(\Rightarrow\left\{{}\begin{matrix}m_{Na_2CO_3}=0,15\cdot106=15,9\left(g\right)\\m_{NaOH}=0,15\cdot40=6\left(g\right)\end{matrix}\right.\)
a)
$Fe + 2HCl \to FeCl_2 + H_2$
Theo PTHH :
$n_{Fe} = n_{H_2} = \dfrac{11,2}{22,4} = 0,5(mol)$
$A = 0,5.56 = 28(gam)$
b) $n_{HCl} = 2n_{H_2} = 1(mol)$
$m_{HCl} = 1.36,5 = 36,5(gam)$
c) $m_{dd\ HCl} = 36,5 : 20\% = 182,5(gam)$
$m_{dd\ sau\ pư} = 28 + 182,5 - 0,5.2 = 209,5(gam)$
$C\%_{FeCl_2} = \dfrac{0,5.127}{209,5}.100\% = 30,3\%$
a) \(n_{Cl_2}=\dfrac{4,48}{22,4}=0,2\left(mol\right)\)
PTHH: 2Fe + 3Cl2 --to--> 2FeCl3
_____\(\dfrac{2}{15}\)<--0,2------------->\(\dfrac{2}{15}\)
=> mFe = \(\dfrac{2}{15}.56=7,467\left(g\right)\)
b) \(m_{FeCl_3}=\dfrac{2}{15}.162,5=21,667\left(g\right)\)
Bài 1:
\(2Na+2H_2O\rightarrow2NaOH+H_2\\ n_{H_2}=\dfrac{4,48}{22,4}=0,2\left(mol\right)\\ n_{Na}=n_{Na_2O}=0,2.2=0,4\left(mol\right)\\ a.m_{Na}=0,4.23=9,2\left(g\right)\\ b.C_{MddA}=\dfrac{0,4}{0,5}=0,8\left(M\right)\\ C\%_{ddA}=\dfrac{0,4.40}{500.1,2}.100\approx2,667\%\)
Câu 1:
\(n_{CO_2}=\dfrac{11,2}{22,4}=0,5(mol)\\ a,PTHH:CO_2+Ba(OH)_2\to BaCO_3\downarrow+H_2O\\ \Rightarrow n_{Ba(OH)_2}=n_{BaCO_3}=n_{CO_2}=0,5(mol)\\ \Rightarrow C_{M_{Ba(OH)_2}}=\dfrac{0,5}{0,2}=2,5M\\ m_{BaCO_3}=0,5.197=98,5(g)\\ b,PTHH:Ba(OH)_2+2HCl\to BaCL_2+2H_2O\\ \Rightarrow n_{HCl}=2n_{Ba(OH)_2}=1(mol)\\ \Rightarrow m_{CT_{HCl}}=1.36,5=36,5(g)\\ \Rightarrow m_{dd_{HCl}}=\dfrac{36,5}{20\%}=182,5(g)\)
Câu 2:
\(n_{Fe_2O_3}=\dfrac{32}{160}=0,2(mol)\\ m_{HCl}=\dfrac{292.20\%}{100\%}=58,4(g)\\ \Rightarrow n_{HCl}=\dfrac{58,4}{36,5}=1,6(mol)\\ PTHH:Fe_2O_3+6HCl\to 2FeCl_3+3H_2O\)
Vì \(\dfrac{n_{HCl}}{6}>\dfrac{n_{Fe_2O_3}}{1}\) nên \(HCl\) dư
\(\Rightarrow n_{FeCl_3}=2n_{Fe_2O_3}=0,4(mol);n_{H_2O}=3n_{Fe_3O_3}=0,6(mol)\\ \Rightarrow \begin{cases} m_{CT_{FeCl_3}}=0,4.162,5=65(g)\\ m_{H_2O}=0,6.18=10,8(g) \end{cases}\\ \Rightarrow m_{dd_{FeCl_3}}=32+292-10,8=313,2(g)\\ \Rightarrow C\%_{FeCl_3}=\dfrac{65}{313,2}.100\%\approx20,75\%\)
PTHH :
\(2Al+6HCl\rightarrow2AlCl_3+3H_2\uparrow\)
x 3x x 1,5x
\(Fe+2HCl\rightarrow FeCl_2+H_2\uparrow\)
y 2y y y
\(n_{H_2}=\dfrac{11,2}{22,4}=0,5\left(mol\right)\)
Gọi n Al = x
n Fe = y (mol )
Ta có hệ PT :
\(\left\{{}\begin{matrix}27x+56y=16,6\\1,5x+y=0,5\end{matrix}\right.\)
Giải hệ PT , ta có :
\(x=y=0,2\left(mol\right)\)
\(m_{Al}=0,2.27=5,4\left(g\right)\)
\(m_{Fe}=16,6-5,4=11,2\left(g\right)\)
a) \(m_{Na2SO4}=0,2.142=28,4\left(g\right)\)
b) \(n_{H2\left(dktc\right)}=\dfrac{11,2}{22,4}=0,5\left(mol\right)\)
\(m_{H2}=0,5.2=1\left(g\right)\)
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