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\(a) n_{Na_2CO_3} = \dfrac{2,12}{106} = 0,02(mol) ; n_{HCl} = 0,5.0,1 = 0,05(mol)\\ Na_2CO_3 + 2HCl \to 2NaCl + CO_2 + H_2O\\ Vì :2n_{Na_2CO_3} = 0,04 < n_{HCl} = 0,05\ nên\ HCl\ \text{dư}\\ n_{CO_2} = n_{Na_2CO_3} = 0,02(mol)\\ V_{CO_2} = 0,02.22,4 = 0,448(lít)\\ b) n_{HCl\ dư} = n_{HCl\ ban\ đầu} - 2n_{Na_2CO_3} = 0,05 -0,02.2 = 0,01(mol)\\ n_{NaCl} = 2n_{Na_2CO_3} = 0,02.2 = 0,04(mol)\\ C_{M_{HCl}} = \dfrac{0,01}{0,5} = 0,02M\\ C_{M_{NaCl}} = \dfrac{0,04}{0,5} = 0,08M\)
a, PT: \(Fe+S\underrightarrow{t^o}FeS\)
Ta có: \(n_{Fe}=\dfrac{16,8}{56}=0,3\left(mol\right)\)
\(n_S=\dfrac{3,2}{32}=0,1\left(mol\right)\)
Xét tỉ lệ: \(\dfrac{0,3}{1}>\dfrac{0,1}{1}\), ta được Fe dư.
Chất rắn A gồm Fe dư và FeS.
Theo PT: \(n_{Fe\left(pư\right)}=n_{FeS}=n_S=0,1\left(mol\right)\)
\(\Rightarrow n_{Fe\left(dư\right)}=0,2\left(mol\right)\)
PT: \(Fe+2HCl\rightarrow FeCl_2+H_2\)
\(FeS+2HCl\rightarrow FeCl_2+H_2S\)
Theo PT: \(\left\{{}\begin{matrix}n_{H_2}=n_{Fe\left(dư\right)}=0,2\left(mol\right)\\n_{H_2S}=n_{FeS}=0,1\left(mol\right)\end{matrix}\right.\)
Ở cùng điều kiện nhiệt độ và áp suất, %V cũng là % số mol.
\(\Rightarrow\left\{{}\begin{matrix}\%V_{H_2}=\dfrac{0,2}{0,2+0,1}.100\%\approx66,67\%\\\%V_{H_2S}\approx33,33\%\end{matrix}\right.\)
b, Ta có: \(\Sigma n_{HCl\left(dadung\right)}=2n_{Fe}+2n_{FeS}=0,6\left(mol\right)\) (1)
PT: \(NaOH+HCl\rightarrow NaCl+H_2O\)
Ta có: \(n_{NaOH}=0,1.2=0,2\left(mol\right)\)
\(\Rightarrow n_{HCl\left(dư\right)}=n_{NaOH}=0,2\left(mol\right)\) (2)
Từ (1) và (2) \(\Rightarrow\Sigma n_{HCl}=0,8\left(mol\right)\)
\(\Rightarrow C_{M_{ddHCl}}=\dfrac{0,8}{0,5}=1,6\left(M\right)\)
Bạn tham khảo nhé!
\(n_{Mg}=\dfrac{6}{24}=0,25\left(mol\right)\\ PTHH:Mg+2HCl\rightarrow MgCl_2+H_2\uparrow\)
0,25 ---> 0,5 ---> 0,25 ---> 0,25
\(V_{H_2}=0,25.22,4=5,6\left(l\right)\\ m_{MgCl_2}=0,25.95=23,75\left(g\right)\\ m_{HCl}=0,5.36,5=18,25\left(g\right)\\ m_{ddHCl}=\dfrac{18,25}{18,25\%}=100\left(g\right)\\ m_{H_2}=0,25.2=0,5\left(g\right)\\ m_{dd}=100+6-0,5=105,5\left(g\right)\\ C\%_{MgCl_2}=\dfrac{23,75}{105,5}=22,51\%\)
\(1.M+2HCl->MCl_2+H_2\\MCO_3+2HCl->MCl_2+CO_2+H_2O\\ n_A=4,48:22,4=0,2mol\\ n_{H_2}=a;n_{CO_2}=b\\ a+b=0,2\\ 2a+44b=0,2.11,5.2\\ a=b=0,1\\ 0,1\left(M+M+60\right)=10,8\\ M=24\left(Mg:magnesium\right)\\ b.\%V_{H_2}=\dfrac{0,1}{0,2}.100\%=50\%\\ \%V_{CO_2}=50\% \)
\(2.M:nguyên.tố.chung\\ a.M+2HCl->MCl_2+H_2\\ n_{H_2}=n_M=\dfrac{3,36}{22,4}=0,15mol\\ M_M=\dfrac{4,4}{0,15}=29,33\\ A,B:liên.tiếp\left(nhóm.IIA\right)\Rightarrow A:Mg\left(24\right),B:Ca\left(40\right)\\ n_{HCl\left(tt\right)}=0,25\cdot0,3:1=0,075\left(L\right)\)
\(n_{HCl} = \dfrac{448.1,12.3,65\%}{36,5} = 0,50176(mol)\\ Zn + 2HCl \to ZnCl_2 + H_2\\ ZnO + 2HCl \to ZnCl_2 + H_2O\\ n_{Zn} = n_{H_2} = \dfrac{2,24}{22,4} = 0,1(mol)\\ n_{ZnO} = \dfrac{n_{HCl} - 2n_{Zn}}{2} = \dfrac{0,50176-0,1.2}{2} = 0,15088(mol)\\ \%m_{Zn} = \dfrac{0,1.65}{0,1.65 + 0,15088.81}.100\% = 34,72\%\\ \%m_{ZnO} = 65,28\%\)
`1)`
`n_{Al}={2,7}/{27}=0,1(mol)`
`2Al+3H_2SO_4->Al_2(SO_4)_3+3H_2`
`0,1->0,15->0,05->0,15(mol)`
`V_{dd\ H_2SO_4}={0,15}/1=0,15(l)=150(ml)`
`->V=150`
`V'=V_{H_2}=0,15.22,4=3,36(l)`
`C_{M\ X}=C_{M\ Al_2(SO_4)_3}={0,05}/{0,15}=1/3M`
`2)`
`n_{Fe}={2,8}/{56}=0,05(mol)`
`Fe+2HCl->FeCl_2+H_2`
`0,05->0,1->0,05->0,05(mol)`
`V_{dd\ HCl}={0,1}/1=0,1(l)=100(ml)`
`->V=100`
`V_{H_2}=0,05.22,4=1,12(l)`
`C_{M\ FeCl_2}={0,05}/{0,1}=0,5M`
\(2Al+6HCl\rightarrow2AlCl_3+3H_2\\ Fe+2HCl\rightarrow FeCl_2+H_2\\ Đặt:n_{Al}=a\left(mol\right);n_{Fe}=b\left(mol\right)\left(a,b>0\right)\\n_{H_2}=\dfrac{2,16}{22,4}=0,09\left(mol\right)\\ \Rightarrow \left\{{}\begin{matrix}1,5a+b=0,09\\27a+56b=2,76\end{matrix}\right.\Leftrightarrow\left\{{}\begin{matrix}a=0,04\\b=0,03\end{matrix}\right.\\ \Rightarrow\%m_{Al}=\dfrac{0,04.27}{2,76}.100\approx39,13\%\\ \Rightarrow\%m_{Fe}\approx100\%-39,13\%\approx60,87\%\)
\(b,V_{ddsau}=V_{ddHCl}=0,2\left(l\right)\\ n_{AlCl_3}=n_{Al}=0,04\left(mol\right);n_{FeCl_2}=n_{Fe}=0,03\left(mol\right)\\ \Rightarrow C_{MddFeCl_2}=\dfrac{0,03}{0,2}=0,15\left(M\right)\\ C_{MddAlCl_3}=\dfrac{0,04}{0,2}=0,2\left(M\right)\)
\(2Al+6HCl\rightarrow2AlCl_3+3H_2\uparrow\)
\(x\) \(1,5x\)
\(Fe+2HCl\rightarrow FeCl_2+H_2\uparrow\)
\(y\) \(y\)
Có \(27x+56y=2,76\left(1\right)\)
\(1,5x+y=\dfrac{2,016}{22,4}=0,09\left(2\right)\)
Từ (1) và (2)\(\Rightarrow\left\{{}\begin{matrix}x=0,04\\y=0,03\end{matrix}\right.\)
\(\%m_{Al}=\dfrac{0,04\cdot27}{2,76}\cdot100\%=39,13\%\)
\(\%m_{Fe}=100\%-39,13\%=60,87\%\)
\(n_{K_2CO_3}=\dfrac{4.14}{138}=0.03\left(mol\right)\)
\(n_{HCl}=0.2\cdot0.35=0.07\left(mol\right)\)
\(K_2CO_3+2HCl\rightarrow2KCl+CO_2+H_2O\)
\(0.03..........0.06.........0.06.......0.03\)
\(V_{CO_2}=0.03\cdot22.4=0.672\left(l\right)\)
\(n_{HCl\left(dư\right)}=0.07-0.06=0.01\left(mol\right)\)
\(C_{M_{HCl\left(dư\right)}}=\dfrac{0.01}{0.2}=0.05\left(M\right)\)
\(C_{M_{KCl}}=\dfrac{0.06}{0.2}=0.3\left(M\right)\)