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a, \(n_{Zn}=\dfrac{6,5}{65}=0,1\left(mol\right)\)
PTHH: Zn + 2HCl ---> ZnCl2 + H2
0,1--->0,2------->0,1----->0,1
VH2 = 0,1.22,4 = 2,24 (l)
b, \(C_{M\left(HCl\right)}=\dfrac{0,2}{0,2}=1M\)
c, \(C_{M\left(ZnCl_2\right)}=\dfrac{0,1}{0,2}=0,5M\)
Ta có: \(m_{HCl}=300.7,3\%=21,9\left(g\right)\Rightarrow n_{HCl}=\dfrac{21,9}{36,5}=0,6\left(mol\right)\)
PT: \(Mg+2HCl\rightarrow MgCl_2+H_2\)
___0,3_____0,6_____0,3____0,3 (mol)
a, mMg = 0,3.24 = 7,2 (g)
b, Ta có: m dd sau pư = mMg + m dd HCl - mH2 = 7,2 + 300 - 0,3.2 = 306,6 (g)
\(\Rightarrow C\%_{MgCl_2}=\dfrac{0,3.95}{306,6}.100\%\approx9,3\%\)
Bạn tham khảo nhé!
pthh:Mg+2HCl→MgCl2+H2(1)
theo pthh=>\(nMg=\dfrac{1}{2}nHCL=\dfrac{300.7,3\%}{7,3}.\dfrac{1}{2}=\dfrac{3.1}{2}=1,5mol\)
=>mMg=\(1,5.24=36g\)
b, theo pthh(1)\(=>nMgCl2=\dfrac{1}{2}nHCL=1,5mol\)
\(=>mMgCl2=\)\(1,5.95=142,5g\)
\(mdd=\text{ m Mg + mdd HCl - m H2}=36+300-1,5.2=333g\)
\(=>\%mMgCl2=\dfrac{142,5}{333}.100\%=42,8\%\)
\(n_{Zn}=\dfrac{26}{65}=0,4\left(mol\right)\\ pthh:Zn+2HCl\rightarrow ZnCl_2+H_2\uparrow\)
0,4 0,8 0,4 0,4
\(a,V_{H_2}=0,4.22,4=8,96\left(l\right)\\ b,C\%_{HCl}=\dfrac{0,8.36,5}{150}.100\%=19,5\%\\ c,m_{\text{dd}}=26+150-\left(0,4.2\right)=175,2\left(g\right)\\ C\%_{ZnCl_2}=\dfrac{0,4.136}{175,2}.100\%=31\%\)
a, \(Fe+2HCl\rightarrow FeCl_2+H_2\)
\(CuO+2HCl\rightarrow CuCl_2+H_2O\)
b, \(n_{Fe}=\dfrac{2,8}{56}=0,05\left(mol\right)\)
Theo PT: \(n_{H_2}=n_{Fe}=0,05\left(mol\right)\Rightarrow V_{H_2}=0,05.22,4=1,12\left(l\right)\)
c, \(n_{CuO}=\dfrac{4}{80}=0,05\left(mol\right)\)
Theo PT: \(n_{HCl}=2n_{Fe}+2n_{CuO}=0,2\left(mol\right)\)
\(\Rightarrow C_{M_{HCl}}=\dfrac{0,2}{0,2}=1\left(M\right)\)
nMg = 6,72 : 22,4 = 0,3 mol
Mg + 2HCl -> MgCl2 + H2
0,3 0,6 0,3
=> mMg = 0,3 . 24 = 7,2 g
CM HCl = 0,6 : 0,5 = 4M
\(n_{Mg}=\dfrac{4.8}{24}=0.2\left(mol\right)\)
\(Mg+2HCl\rightarrow MgCl_2+H_2\)
\(0.2.......0.4........................0.2\)
\(C_{M_{HCl}}=\dfrac{0.4}{0.2}=2\left(M\right)\)
\(n_{CuO}=\dfrac{32}{80}=0.4\left(mol\right)\)
\(CuO+H_2\underrightarrow{^{^{t^0}}}Cu+H_2O\)
Lập tỉ lệ : \(\dfrac{0.4}{1}>\dfrac{0.2}{1}\)
=> CuO dư
\(m_{cr}=m_{CuO\left(dư\right)}+m_{Cu}=32-0.2\cdot80+0.2\cdot64=28.8\left(g\right)\)
\(\%Cu=\dfrac{0.2\cdot64}{28.8}\cdot100\%=44.44\%\)
\(\%CuO\left(dư\right)=55.56\%\)
a, \(n_{Zn}=\dfrac{6,5}{65}=0,1\left(mol\right)\)
PT: \(Zn+2HCl\rightarrow ZnCl_2+H_2\)
____0,1_____0,2______0,1_____0,1 (mol)
\(V_{H_2}=0,1.24,79=2,479\left(l\right)\)
\(m_{ZnCl_2}=0,1.136=13,6\left(g\right)\)
b, \(C_{M_{HCl}}=\dfrac{0,2}{0,1}=1\left(M\right)\)
c, \(n_{CuO}=\dfrac{12}{80}=0,15\left(mol\right)\)
PT: \(CuO+H_2\underrightarrow{t^o}Cu+H_2O\)
Xét tỉ lệ: \(\dfrac{0,15}{1}>\dfrac{0,1}{1}\), ta được CuO dư.
Theo PT: \(n_{CuO\left(pư\right)}=n_{Cu}=n_{H_2}=0,1\left(mol\right)\Rightarrow n_{CuO\left(dư\right)}=0,05\left(mol\right)\)
⇒ m chất rắn = mCuO (dư) + mCu = 0,05.80 + 0,1.64 = 10,4 (g)
\(a.2Al+6HCl\rightarrow2AlCl_3+3H_2\\ b.n_{Al}=0,2\left(mol\right)\\ n_{HCl}=3n_{Al}=0,6\left(mol\right)\\ C\%_{HCl}=\dfrac{0,6.36,5}{150}.100=14,6\%\\ c.n_{H_2}=\dfrac{3}{2}n_{Al}=0,3\left(mol\right)\\ Bảotòannguyêntố\left(H\right)\Rightarrow n_{H_2O}=n_{H_2}=0,3\left(mol\right)\\ Bảotoànkhốilượng:m_{H_2}+m_{oxit}=m_{Fe}+m_{H_2O}\\ \Rightarrow m_{Fe}=0,3.2+17,4-0,3.18=12,6\left(g\right)\\ \Rightarrow n_{Fe}=0,225\left(mol\right)\\ Tabiết:Oxitsắtlàbaogồm:Fe,O\\ \Rightarrow m_O=17,4-12,6=4,8\left(g\right)\\ \Rightarrow n_O=0,3\left(mol\right)\\ GọiCToxitsắtlà:Fe_xO_y\left(x,y>0,x,ynguyên\right)\\ Tacó:x:y=0,225:0,3=3:4\\ VậyCToxitsắtcầntìmlàFe_3O_4\)
\(n_{Fe}=\dfrac{22,4}{56}=0,4mol\)
\(Fe+2HCl\rightarrow FeCl_2+H_2\)
0,4 0,8 0,4
\(C_{M_{HCl}}=\dfrac{0,8}{0,4}=2M\)
\(V_{H_2}=0,4\cdot22,4=8,96l\)
Ta có: \(n_{Mg}=\dfrac{9,6}{24}=0,4\left(mol\right)\)
PT: \(Mg+2HCl\rightarrow MgCl_2+H_2\)
Theo PT: \(n_{HCl}=2n_{Mg}=0,8\left(mol\right)\)
\(\Rightarrow C_{M_{HCl}}=\dfrac{0,8}{0,2}=4\left(M\right)\)