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nH2=0,1(mol)
PTHH: Mg + 2 HCl -> MgCl2 + H2
0,1__________0,2___________0,1(mol)
MgO + 2 HCl -> MgCl2 + H2O
0,05____0,1___0,05(mol)
mMg=0,1. 24= 2,4(g) -> mMgO=4,4-2,4= 2(g) -> nMgO=0,05((mol)
b) %mMg= (2,4/4,4).100=54,545%
=> %mMgO=45,455%
c) nHCl=0,3(mol) -> mHCl=0,3.36,5=10,95(g)
=> mddHCl=(10,95.100)/7,3=150(g)
Tiếp bài của creeper nhé:
c. Ta có: \(n_{ZnO}=\dfrac{4,86}{81}=0,06\left(mol\right)\)
Theo PT(1): \(n_{HCl}=2.n_{ZnO}=2.0,06=0,12\left(mol\right)\)
Theo PT(2): \(n_{HCl}=2.n_{Zn}=2.0,1=0,2\left(mol\right)\)
=> \(n_{HCl}=0,12+0,2=0,32\left(mol\right)\)
=> \(m_{HCl}=0,32.36,5=11,68\left(g\right)\)
Ta có: \(C_{\%_{HCl}}=\dfrac{11,68}{m_{dd_{HCl}}}.100\%=12\%\)
=> \(m_{dd_{HCl}}=\dfrac{292}{3}\left(g\right)\)
Theo đề, ta có:
\(D=\dfrac{\dfrac{292}{3}}{V_{dd_{HCl}}}=1,2\)(g/ml)
=> \(V_{dd_{HCl}}=81,1\left(ml\right)\)
C32:
a, \(n_C=\dfrac{2,4}{12}=0,2\left(mol\right)\)
PT: \(C+O_2\underrightarrow{t^o}CO_2\)
Theo PT: \(n_{CO_2}=n_C=0,2\left(mol\right)\Rightarrow V_{CO_2}=0,2.22,4=4,48\left(l\right)\)
b, \(n_{NaOH}=0,3.1=0,3\left(mol\right)\)
\(\Rightarrow\dfrac{n_{NaOH}}{n_{CO_2}}=1,5\) → Pư tạo NaHCO3 và Na2CO3
PT: \(CO_2+NaOH\rightarrow NaHCO_3\)
\(CO_2+2NaOH\rightarrow Na_2CO_3+H_2O\)
Ta có: \(\left\{{}\begin{matrix}n_{CO_2}=n_{NaHCO_3}+n_{Na_2CO_3}=0,2\\n_{NaOH}=n_{NaHCO_3}+2n_{Na_2CO_3}=0,3\end{matrix}\right.\)
\(\Rightarrow\left\{{}\begin{matrix}n_{NaHCO_3}=0,1\left(mol\right)\\n_{Na_2CO_3}=0,1\left(mol\right)\end{matrix}\right.\)
⇒ mNaHCO3 = 0,1.84 = 8,4 (g)
mNa2CO3 = 0,1.106 = 10,6 (g)
c, \(C_{M_{NaHCO_3}}=C_{M_{Na_2CO_3}}=\dfrac{0,1}{0,3}=\dfrac{1}{3}\left(M\right)\)
Lần sau bạn đăng tách câu hỏi ra nhé.
C31:
a, \(Zn+2HCl\rightarrow ZnCl_2+H_2\)
\(ZnO+2HCl\rightarrow ZnCl_2+H_2O\)
b, \(n_{H_2}=\dfrac{2,24}{22,4}=0,1\left(mol\right)\)
Theo PT: \(n_{Zn}=n_{H_2}=0,1\left(mol\right)\)
\(\Rightarrow\left\{{}\begin{matrix}\%m_{Zn}=\dfrac{0,1.65}{14,6}.100\%\approx44,52\%\\\%m_{ZnO}\approx55,48\%\end{matrix}\right.\)
c, \(n_{ZnO}=\dfrac{14,6-0,1.65}{81}=0,1\left(mol\right)\)
Theo PT: \(n_{HCl}=2n_{Zn}+2n_{ZnO}=0,4\left(mol\right)\)
\(\Rightarrow m_{ddHCl}=\dfrac{0,4.36,5}{10\%}=146\left(g\right)\)
PTHH: \(Fe+2HCl\rightarrow FeCl_2+H_2\uparrow\)
\(Fe_2O_3+6HCl\rightarrow2FeCl_3+3H_2O\)
a) Ta có: \(n_{H_2}=\dfrac{4,48}{22,4}=0,2\left(mol\right)=n_{Fe}\)
\(\Rightarrow m_{Fe}=0,2\cdot56=11,2\left(g\right)\) \(\Rightarrow m_{Fe_2O_3}=16\left(g\right)\)
b+c) Ta có: \(\left\{{}\begin{matrix}n_{Fe}=0,2\left(mol\right)\\n_{Fe_2O_3}=\dfrac{16}{160}=0,1\left(mol\right)\end{matrix}\right.\)
\(\Rightarrow n_{HCl}=2n_{Fe}+6n_{Fe_2O_3}=1\left(mol\right)\) \(\Rightarrow m_{ddHCl}=\dfrac{36,5}{20\%}=182,5\left(g\right)\)
Mặt khác: \(n_{FeCl_2}=0,2\left(mol\right)=n_{H_2}=n_{FeCl_3}\) \(\Rightarrow\left\{{}\begin{matrix}m_{FeCl_2}=0,2\cdot127=25,4\left(g\right)\\m_{FeCl_3}=0,2\cdot162,5=32,5\left(g\right)\\m_{H_2}=0,2\cdot2=0,4\left(g\right)\end{matrix}\right.\)
\(\Rightarrow m_{dd}=m_{hhA}+m_{ddHCl}-m_{H_2}=209,3\left(g\right)\)
\(\Rightarrow\left\{{}\begin{matrix}C\%_{FeCl_2}=\dfrac{25,4}{209,3}\cdot100\%\approx12,14\%\\C\%_{FeCl_3}=\dfrac{32,5}{209,3}\cdot100\%\approx15,53\%\end{matrix}\right.\)
\(n_{H2}=\dfrac{4,48}{22,4}=0,2\left(mol\right)\)
Pt : \(Fe+2HCl\rightarrow FeCl_2+H_2|\)
1 2 1 1
0,2 0,4 0,2 0,2
\(Fe_2O_3+6HCl\rightarrow2FeCl_3+3H_2O|\)
1 6 2 3
0,1 0,6 0,2
a) \(n_{Fe}=\dfrac{0,2.1}{1}=0,2\left(mol\right)\)
\(m_{Fe}=0,2.56=11,2\left(g\right)\)
\(m_{Fe2O3}=27,2-11,2=16\left(g\right)\)
b) Có : \(m_{Fe2O3}=16\left(g\right)\)
\(n_{Fe2O3}=\dfrac{16}{160}=0,1\left(mol\right)\)
\(n_{HCl\left(tổng\right)}=0,4+0,6=1\left(mol\right)\)
⇒ \(m_{HCl}=1.36,5=36,5\left(g\right)\)
\(m_{ddHCl}=\dfrac{36,5.100}{20}=182,5\left(g\right)\)
c) \(n_{FeCl2}=\dfrac{0,2.1}{1}=0,2\left(mol\right)\)
⇒ \(m_{FeCl2}=0,2.127=25,4\left(g\right)\)
\(n_{FeCl3}=\dfrac{0,6.2}{6}=0,2\left(mol\right)\)
⇒ \(m_{FeCl3}=0,2.162,5=32,5\left(g\right)\)
\(m_{ddspu}=27,2+182,5-\left(0,2.2\right)=209,3\left(g\right)\)
\(C_{FeCl2}=\dfrac{25,4.100}{209,3}=12,14\)0/0
\(C_{FeCl3}=\dfrac{32,5.100}{209,3}=15,53\)0/0
Chúc bạn học tốt
Gọi x,y,z lần lượt là số mol của Al,Mg,Zn
PT:
2Al + 6HCl--->2AlCl3 + 3H2
x-------3x----------------------1,5x mol
Mg + 2HCl--->MgCl2 + H2
y-----2y----------------------y mol
Zn + 2HCl--->ZnCl2 + H2
z----2z--------------------z mol
b.
Số mol H2: nH2=16,352/22,4=0,73 mol
1,5x+y+z=0,73
27x = 24y =>x=8y/9
=>7y/3 +z =0,73 (*)
27x + 24y + 65z=19,6
27x = 24y
=> 48y + 65z =19,6 (**)
Từ (*),(**)
=>y=0,27 => mMg =6,48 g
z=0,1=>mZn = 6,5 g
x=0,24=>mAl =6,48g
c.
nHCl =2nH2
=>nHCl =2.0,73=1,46 mol
=>V dd=1,46/2=0,73(l)
PTHH: \(Mg+2HCl\rightarrow MgCl_2+H_2\uparrow\) (1)
\(MgO+2HCl\rightarrow MgCl_2+H_2O\) (2)
a) Ta có: \(n_{H_2}=\dfrac{22,4}{22,4}=1\left(mol\right)=n_{Mg}\) \(\Rightarrow m_{Mg}=1\cdot24=24\left(g\right)\)
\(\Rightarrow\%m_{Mg}=\dfrac{24}{32}\cdot100\%=75\%\) \(\Rightarrow\%m_{MgO}=25\%\)
b) Theo 2 PTHH: \(\left\{{}\begin{matrix}n_{HCl\left(1\right)}=2n_{Mg}=2mol\\n_{HCl\left(2\right)}=2n_{MgO}=2\cdot\dfrac{32-24}{40}=0,4mol\end{matrix}\right.\)
\(\Rightarrow\Sigma n_{HCl}=2,4mol\) \(\Rightarrow m_{ddHCl}=\dfrac{2,4\cdot36,5}{7,3\%}=1200\left(g\right)\)
c) Theo PTHH: \(\Sigma n_{MgCl_2}=\dfrac{1}{2}\Sigma n_{HCl}=1,2mol\)
\(\Rightarrow\Sigma m_{MgCl_2}=1,2\cdot95=114\left(g\right)\)
Mặt khác: \(m_{H_2}=1\cdot2=2\left(g\right)\)
\(\Rightarrow m_{dd}=m_{hh}+m_{ddHCl}-m_{H_2}=1230\left(g\right)\)
\(\Rightarrow C\%_{MgCl_2}=\dfrac{114}{1230}\cdot100\%\approx9,27\%\)
a. PTHH:
\(BaO+2HCl--->BaCl_2+H_2O\left(1\right)\)
\(BaCO_3+2HCl--->BaCl_2+CO_2\uparrow+H_2O\left(2\right)\)
Ta có: \(n_{CO_2}=\dfrac{4,48}{22,4}=0,2\left(mol\right)\)
Theo PT(2): \(n_{BaCO_3}=n_{CO_2}=0,2\left(mol\right)\)
\(\Rightarrow m_{BaCO_3}=0,2.197=39,4\left(g\right)\)
\(\Rightarrow\%_{m_{BaCO_3}}=\dfrac{39,4}{54,7}.100\%=72,03\%\)
\(\%_{m_{BaO}}=100\%-72,03\%=27,97\%\)
b. Ta có: \(m_{BaO}=54,7-39,4=15,3\left(g\right)\)
\(\Rightarrow n_{BaO}=\dfrac{15,3}{153}=0,1\left(mol\right)\)
\(\Rightarrow n_A=0,1+0,2=0,3\left(mol\right)\)
Theo PT(1,2): \(n_{HCl}=2.n_A=2.0,3=0,6\left(mol\right)\)
\(\Rightarrow m_{HCl}=0,6.36,5=21,9\left(g\right)\)
Ta có: \(C_{\%_{HCl}}=\dfrac{21,9}{m_{dd_{HCl}}}.100\%=20\%\)
\(\Rightarrow m_{dd_{HCl}}=109,5\left(g\right)\)
\(n_{CO2}=\dfrac{4,48}{22,4}=0,2\left(mol\right)\)
a) Pt : \(BaO+2HCl\rightarrow BaCl_2+H_2O|\)
1 2 1 1
0,1 0,2
\(BaCO_3+2HCl\rightarrow BaCl_2+CO_2+H_2O|\)
1 2 1 1 1
0,2 0,4 0,2
\(n_{BaCO3}=\dfrac{0,2.1}{1}=0,2\left(mol\right)\)
\(m_{BaCO3}=0,2.197=39,4\left(g\right)\)
\(m_{BaO}=54,7-39,4=15,3\left(g\right)\)
0/0BaO = \(\dfrac{15,3.100}{54,7}=27,97\)0/0
0/0BaCO3 = \(\dfrac{39,4.100}{54,7}=72,03\)0/0
b) Có : \(m_{BaO}=15,3\left(g\right)\)
\(n_{BaO}=\dfrac{15,3}{153}=0,1\left(mol\right)\)
\(n_{HCl\left(tổng\right)}=0,2+0,4=0,6\left(mol\right)\)
\(m_{HCl}=0,6.36,5=21,9\left(g\right)\)
\(m_{ddHCl}=\dfrac{21,9.100}{20}=109,5\left(g\right)\)
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