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Câu 3 :
\(n_{Mg}=\dfrac{4,8}{24}=0,2\left(mol\right)\)
a) Pt : \(Mg+2HCl\rightarrow MgCl_2+H_2|\)
1 2 1 1
0,2 0,4 0,2 0,2
b) \(n_{HCl}=\dfrac{0,2.2}{1}=0,4\left(mol\right)\)
\(m_{HCl}=0,4.36,5=14,6\left(g\right)\)
\(m_{ddHCl}=\dfrac{14,6.100}{10,95}=133,3\left(g\right)\)
c) \(n_{H2}=\dfrac{0,4.1}{2}=0,2\left(mol\right)\)
\(V_{H2\left(dktc\right)}=0,2.22,4=4,48\left(l\right)\)
d) \(n_{MgCl2}=\dfrac{0,2.1}{1}=0,2\left(mol\right)\)
⇒ \(m_{MgCl2}=0,2.95=19\left(g\right)\)
\(m_{ddspu}=4,8+133,3-\left(0,2.2\right)=137,7\left(g\right)\)
\(C_{MgCl2}=\dfrac{19.100}{137,7}=13,8\)0/0
Chúc bạn học tốt
\(a)Mg+2HCl\rightarrow MgCl_2+H_2\\ n_{Mg}=\dfrac{5,28}{24}=0,22mol\\ Mg+2HCl\rightarrow MgCl_2+H_2\\ 0,22...0,44........0,22........0,22\\ V_{H_2\left(đkc\right)}=0,22.24,79=5,4538l\\ b)C_{\%HCl}=\dfrac{0,44.26,5}{200}\cdot100=8,03\%\\ c)C_{\%MgCl_2}=\dfrac{0,22.95}{200+5,28}\cdot100\approx10,18\%\)
a) $CaCO_3 + 2HCl \to CaCl_2 + CO_2 + H_2O$
Theo PTHH :
$n_{CO_2} = n_{CaCO_3} = \dfrac{10}{100} = 0,1(mol)$
$V_{CO_2} = 0,1.22,4 = 2,24(lít)$
b) $n_{HCl} = 2n_{CaCO_3} = 0,2(mol)$
$C_{M_{HCl}} = \dfrac{0,2}{0,25} = 0,8M$
c) $CO_2 + Ca(OH)_2 \to CaCO_3 + H_2O$
$n_{CaCO_3} = n_{CO_2} = 0,1(mol)$
$m_{CaCO_3} = 0,1.100 = 10(gam)$
Mg+ 2HCl→ MgCl2+ H2
(mol) 0,1 0,2 0,1 0,1
a) \(n_{Mg}=\dfrac{m}{M}=\dfrac{2,4}{24}=0,1\left(mol\right)\)
→\(V_{H_2}=n.22,4=0,1.22,4=2,24\left(lít\right)\)
b) Đổi: 100ml=0,1 lít
\(C_{M_{HCl}}=\dfrac{n}{V}=\dfrac{0,2}{0,1}=2M\)
c) \(m_{MgCl_2}=n.M=0,1.95=9,5\left(g\right)\)
a) \(n_{Al}=\dfrac{5,4}{27}=0,2\left(mol\right)\)
PTHH: 2Al + 3H2SO4 --> Al2(SO4)3 + 3H2
______0,2---->0,3------------>0,1------>0,3______(mol)
=> VH2 = 0,3.22,4= 6,72(l)
b) \(C_{M\left(H_2SO_4\right)}=\dfrac{0,3}{0,1}=3M\)
\(C_{M\left(Al_2\left(SO_4\right)_3\right)}=\dfrac{0,1}{0,1}=1M\)
Câu 3:
\(n_{H_2}=\dfrac{6,72}{22,4}=0,3(mol)\\ PTHH:Mg+2HCl\to MgCl_2+H_2\\ MgO+2HCl\to MgCl_2+H_2O\\ \Rightarrow n_{Mg}=n_{H_2}=0,3(mol)\\ \Rightarrow \%_{Mg}=\dfrac{0,3.24}{15,2}.100\%=47,37\%\\ \Rightarrow \%_{MgO}=100\%-47,37\%=52,63\%\)
\(n_{MgO}=\dfrac{15,2-0,3.24}{40}=0,2(mol)\\ \Rightarrow \Sigma n_{HCl}=0,3.2+0,2.2=1(mol)\\ \Rightarrow m_{dd_{HCl}}=\dfrac{1.36,5}{10\%}=365(g)\\ \Sigma n_{MgCl_2}=0,2+0,3=0,5(mol)\\ \Rightarrow C\%_{MgCl_2}=\dfrac{0,5.95}{15,2+365}.100\%=12,49\%\)
\(PTHH:Mg+2H_2SO_{4(đ)}\to MgSO_4+2H_2O+SO_2\uparrow\\ MgO+H_2SO_4\to MgSO_4+H_2O\\ \Rightarrow n_{SO_2}=n_{Mg}=0,3(mol)\\ \Rightarrow V_{SO_2}=0,3.22,4=6,72(l)\)
nH2=\(\frac{6,72}{22,4}=0,3\)mol
PTHH
M+2HCl--> MCl2+H2
0,3mol<---------------0,3mol
=>MM=\(\frac{19,5}{0,3}=64\)
=> km loại là kẽm (Zn)
b) nNaOH=0,2.1=0,2 mol
PTHH
NaOH+HCl-->NaCl + H2O
0,2 mol--> 0,2 mol
---> thể tích HCl 1M đã dùng là V=\(\frac{0,2+0,3}{1}=0,5\)lít
=> CM(ZnCl2)=\(\frac{0,3}{0,5}=0,6M\)
Ta có: \(n_{Mg}=\dfrac{4,8}{24}=0,2\left(mol\right)\)
PT: \(Mg+2HCl\rightarrow MgCl_2+H_2\)
a, \(n_{HCl}=2n_{Mg}=0,4\left(mol\right)\Rightarrow V_{ddHCl}=\dfrac{0,4}{1}=0,4\left(l\right)\)
b, \(n_{H_2}=n_{Mg}=0,2\left(mol\right)\) \(\Rightarrow V_{H_2}=0,2.22,4=4,48\left(l\right)\)
c, \(n_{MgCl_2}=n_{Mg}=0,2\left(mol\right)\Rightarrow C_{M_{MgCl_2}}=\dfrac{0,2}{0,4}=0,5\left(M\right)\)
0,4 mình lấy ở đâu vậy ạ