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Ta có: \(n_{H_2}=\dfrac{4,2}{22,4}=0,1875\left(mol\right)\)
PT: \(2Al+6HCl\rightarrow2AlCl_3+3H_2\)
__0,125__0,375___________0,1875 (mol)
\(\Rightarrow m_{Al}=0,125.27=3,375\left(g\right)\)
\(V_{HCl}=\dfrac{0,375}{3}=0,125\left(l\right)=125\left(ml\right)\)
Bạn tham khảo nhé!
\(a.2Al+6HCl\rightarrow2AlCl_3+3H_2\\ b.n_{Al}=\dfrac{8,1}{27}=0,3mol\\ 2Al+6HCl\rightarrow2AlCl_3+3H_2\)
0,3 0,9 0,3 0,45
\(m_{HCl}=0,9.36,5=32,85g\\ c.V_{H_2}=0,45.24,79=11,1555l\)
a)2Al + 6HCl → 2AlCl3 + 3H2
0,3 0,9 0,45
b)
nAl= \(\dfrac{8,1}{27}=0,3\)
=>mHCl= 0,9. 36,5 = 32,85
c)
=> VH2= 0,45.22,4= 10,08l
Có j k hiểu hỏi mình nhá
\(n_{Mg}=\dfrac{4,8}{24}=0,2\left(mol\right)\\ Mg+2HCl\rightarrow MgCl_2+H_2\\ n_{HCl}=2.0,2=0,4\left(mol\right)\\ a,V_{ddHCl}=\dfrac{0,4}{2}=0,2\left(l\right)\\ b,V_{ddMgCl_2}=V_{ddHCl}=0,2\left(l\right)\\ n_{MgCl_2}=n_{Mg}=0,2\left(mol\right)\\ C_{MddMgCl_2}=\dfrac{0,2}{0,2}=1\left(M\right)\)
a) \(n_{Fe}=\dfrac{8,4}{56}=0,15\left(mol\right)\)
PTHH: Fe + 2HCl --> FeCl2 + H2
0,15->0,3------------->0,15
=> VH2 = 0,15.22,4 = 3,36 (l)
b) \(C\%\left(dd.HCl\right)=\dfrac{0,3.36,5}{100}.100\%=10,95\%\)
Zn+2HCl->ZnCl2+H2
0,1--0,2----0,1-----0,1
n Zn=0,1 mol
=>m ZnCl2=0,1.136=13,6g
=>CMHCl=\(\dfrac{0,2}{0,3}=0,67M\)
\(n_{Zn}=\dfrac{6,5}{65}=0,1\left(mol\right)\\
pthh:Zn+2HCl\rightarrow ZnCl_2+H_2\)
0,1 0,2 0,1 0,1
\(m_{ZnCl_2}=136.0,1=13,6g\\
V_{H_2}=0,1.22,4=2,24l\\
C_{M\left(HCl\right)}=\dfrac{0,2}{0,3}=0,6M\)
Gọi \(\left\{{}\begin{matrix}n_{Al}=a\left(mol\right)\\n_{Fe}=b\left(mol\right)\end{matrix}\right.\)
\(n_{HCl}=0,1.1,2=0,12\left(mol\right)\\ n_{H_2}=0,05\left(mol\right)\)
PTHH:
2Al + 6HCl ---> 2AlCl3 + 3H2
a 3a a 1,5a
Fe + 2HCl ---> FeCl2 + H2
b 2b b b
Hệ pt \(\left\{{}\begin{matrix}27a+56b=1,66\\1,5a+b=0,05\end{matrix}\right.\Leftrightarrow a=b=0,02\left(mol\right)\)
\(\rightarrow\left\{{}\begin{matrix}m_{Al}=0,02.27=0,54\left(g\right)\\m_{Fe}=0,02.56=1,12\left(g\right)\end{matrix}\right.\)
\(\rightarrow\left\{{}\begin{matrix}C_{M\left(AlCl_3\right)}=\dfrac{0,02}{0,1}=0,2M\\C_{M\left(FeCl_2\right)}=\dfrac{0,02}{0,1}=0,2M\\C_{M\left(HCl.dư\right)}=\dfrac{0,12-0,02.3-0,02.2}{0,1}=0,2M\end{matrix}\right.\)
\(\text{1)}m_{KOH}=40.35\%=14\left(g\right)\\ \rightarrow n_{KOH}=\dfrac{14}{56}=0,25\left(mol\right)\\ PTHH:KOH+HCl\rightarrow KCl+H_2O\\ \text{Theo pthh}:n_{HCl}=n_{KOH}=0,25\left(mol\right)\\ \rightarrow V_{ddHCl}=0,25.0,5=0,125\left(l\right)\)
\(\text{2)}n_{Al}=\dfrac{4,05}{27}=0,15\left(mol\right)\\ n_{H_2SO_4}=200.14,7\%=29,4\left(g\right)\\ \rightarrow n_{H_2SO_4}=\dfrac{29,4}{98}=0,3\\ \text{PTHH}:2Al+3H_2SO_4\rightarrow Al_2\left(SO_4\right)_3+3H_2\uparrow\\ \text{LTL}:\dfrac{0,15}{2}< \dfrac{0,3}{3}\rightarrow H_2SO_4\text{ dư}\)
\(\text{Theo pthh}:\left\{{}\begin{matrix}n_{H_2SO_4\left(pư\right)}=\dfrac{3}{2}n_{Al}=\dfrac{3}{2}.0,15=0,225\left(mol\right)\\n_{H_2}=n_{H_2SO_4\left(pư\right)}=0,225\left(mol\right)\\n_{Al_2\left(SO_4\right)_3}=\dfrac{1}{2}n_{Al}=\dfrac{1}{2}.0,15=0,075\left(mol\right)\end{matrix}\right.\\ \rightarrow m_{dd\left(\text{sau phản ứng}\right)}=200+4,05-0,3.2=203,45\left(g\right)\)
\(\rightarrow\left\{{}\begin{matrix}C\%_{H_2SO_4\text{ dư}}=\dfrac{\left(0,3-0,225\right).98}{203,45}=3,61\%\\C\%_{Al_2\left(SO_4\right)_3}=\dfrac{342.0,075}{203,45}=12,61\%\end{matrix}\right.\)
\(a)2Al+6HCl\xrightarrow[]{}2AlCl_3+3H_2\\b) n_{Al}=\dfrac{2,7}{27}=0,1\left(mol\right)\\ n_{H_2}=\dfrac{0,1.3}{2}=0,15\left(mol\right)\\ V_{H_2}=0,15.22,4=3,36\left(l\right)\\ c)n_{AlCl_3}=\dfrac{0,1.2}{2}=0,1\left(mol\right)\\ C_{MAlCl_3}=\dfrac{0,1}{0,35}=\dfrac{2}{7}\left(M\right)\)