Hòa tan hết 11,2g Fe cần vừa đủ 200g dung dịch HCL. a, tính thể tích khí H2 thoát ra ở đktc. b, tính C% của dung dịch HCl cần dùng .c, tính C% của dung dịch sau phản ứng.
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a)
\(n_{Zn}=\dfrac{13}{65}=0,2\left(mol\right)\)
PTHH: Zn + 2HCl --> ZnCl2 + H2
0,2-->0,4----->0,2--->0,2
=> VH2 = 0,2.22,4 = 4,48 (l)
b) mHCl = 0,4.36,5 = 14,6 (g)
=> \(m_{dd.HCl}=\dfrac{14,6.100}{7,3}=200\left(g\right)\)
c)
mdd sau pư = 13 + 200 - 0,2.2 = 212,6 (g)
mZnCl2 = 0,2.136 = 27,2 (g)
=> \(C\%=\dfrac{27,2}{212,6}.100\%=12,8\%\)
a,\(n_{Fe}=\dfrac{28}{56}=0,5\left(mol\right)\)
PTHH: Fe + 2HCl → FeCl2 + H2
Mol: 0,5 1 0,5 0,5
\(V_{ddHCl}=\dfrac{1}{2}=0,5\left(l\right)\)
b,\(V_{H_2}=0,5.22,4=11,2\left(l\right)\)
c,\(C_{M_{ddFeCl_2}}=\dfrac{0,5}{0,5}=1M\)
a) \(n_{Fe}=\dfrac{2,8}{56}=0,05\left(mol\right)\)
PTHH: `Fe + 2HCl -> FeCl_2 + H_2`
0,05->0,1----->0,05---->0,05
`=> V_{ddHCl} = (0,1)/2 = 0,05 (l)`
b) `V_{H_2} = 0,05.22,4 = 1,12 (l)`
c) `C_{M(FeCl_2)} = (0,05)/(0,05) = 1M`
\(n_{Fe}=\dfrac{8,4}{56}=0,15\left(mol\right)\)
PTHH:
\(Fe+2HCl\rightarrow FeCl_2+H_2\)
0,15 0,3 0,15
\(a,V_{H_2}=0,15.22,4=3,36\left(l\right)\)
\(b,C_{M_{HCl}}=\dfrac{n}{V}=\dfrac{0,3}{0,1}=3M\)
Bài 1: Ta có: \(n_{H_2}=\dfrac{1,008}{22,4}=0,045\left(mol\right)\)
PT: \(Mg+2HCl\rightarrow MgCl_2+H_2\)
__0,045__0,09____0,045___0,045 (mol)
a, Ta có: \(a=m_{Mg}=0,045.24=1,08\left(g\right)\)
b, \(V_{ddHCl}=\dfrac{0,09}{0,1}=0,9\left(l\right)\)
c, \(C_{M_{MgCl_2}}=\dfrac{0,045}{0,9}=0,05M\)
Bài 2:
PT: \(Mg+2HCl\rightarrow MgCl_2+H_2\)
\(Fe+2HCl\rightarrow FeCl_2+H_2\)
a, Giả sử: \(\left\{{}\begin{matrix}n_{Mg}=x\left(mol\right)\\n_{Fe}=y\left(mol\right)\end{matrix}\right.\)
⇒ 24x + 56y = 5,2 (1)
Ta có: \(n_{H_2}=\dfrac{3,36}{22,4}=0,15\left(mol\right)\)
Theo PT: \(n_{H_2}=n_{Mg}+n_{Fe}=x+y\left(mol\right)\)
⇒ x + y = 0,15 (2)
Từ (1) và (2) \(\Rightarrow\left\{{}\begin{matrix}x=0,1\left(mol\right)\\y=0,05\left(mol\right)\end{matrix}\right.\)
\(\Rightarrow\left\{{}\begin{matrix}\%m_{Mg}=\dfrac{0,1.24}{5,2}.100\%\approx46,2\%\\\%m_{Fe}\approx53,8\%\end{matrix}\right.\)
b, Ta có: \(n_{HCl}=2n_{H_2}=0,3\left(mol\right)\)
\(\Rightarrow V_{HCl}=\dfrac{0,3}{1}=0,3\left(l\right)\)
Bạn tham khảo nhé!
a, \(Zn+2HCl\rightarrow ZnCl_2+H_2\)
b, \(n_{Zn}=\dfrac{13}{65}=0,2\left(mol\right)\)
Theo PT: \(n_{H_2}=n_{Zn}=0,2\left(mol\right)\Rightarrow V_{H_2}=0,2.22,4=4,48\left(l\right)\)
c, \(n_{HCl}=2n_{Zn}=0,4\left(mol\right)\Rightarrow m_{HCl}=0,4.36,5=14,6\left(g\right)\)
\(\Rightarrow m_{ddHCl}=\dfrac{14,6}{10,95\%}=\dfrac{400}{3}\left(g\right)\)
d, \(n_{ZnCl_2}=n_{Zn}=0,2\left(mol\right)\)
Ta có: m dd sau pư = 13 + 400/3 - 0,2.2 = 2189/15 (g)
\(\Rightarrow C\%_{ZnCl_2}=\dfrac{0,2.136}{\dfrac{2189}{15}}.100\%\approx18,64\%\)
a.
PTHH:
Zn + 2HCl ---> ZnCl2 + H2
0.2 0.4 0.2 0.2 (mol)
b.
nZn=13/65=0.2(mol)
V H2 = 0.2*22.4 = 4.48 (l)
c.
mHCl=0.4*36.5=14.6(g)
mddHCl=14.6/10.95*100~133(g)
d.
mZn=0.2*35.5=7.1(g)
mZnCl2=0.2*106=21.2(g)
mH2=0.2*2=0.4(g)
Theo ĐLBTKL, ta có:
mZn + mddHCl = mddZnCl2 + mH2
7.1 + 133 = mddZnCl2 + 4
=> mddZnCl2= 7.1 + 133 - 4 = 136.1 (g)
S ZnCl2= 21.2/136.1*100 ~ 15 (g)
a, \(Zn+2HCl\rightarrow ZnCl_2+H_2\)
b, \(n_{Zn}=\dfrac{13}{65}=0,2\left(mol\right)\)
Theo PT: \(n_{H_2}=n_{Zn}=0,2\left(mol\right)\Rightarrow V_{H_2}=0,2.22,4=4,48\left(l\right)\)
c, \(n_{ZnCl_2}=n_{Zn}=0,2\left(mol\right)\Rightarrow m_{ZnCl_2}=0,2.136=27,2\left(g\right)\)
d, \(n_{HCl}=2n_{Zn}=0,4\left(mol\right)\Rightarrow m_{HCl}=0,4.36,5=14,6\left(g\right)\)
\(\Rightarrow m_{ddHCl}=\dfrac{14,6}{7,3\%}=200\left(g\right)\)
⇒ m dd sau pư = 13 + 200 - 0,2.2 = 212,6 (g)
\(\Rightarrow C\%_{ZnCl_2}=\dfrac{27,2}{212,6}.100\%\approx12,79\%\)
a, \(n_{Al}=\dfrac{2,7}{27}=0,1\left(mol\right)\)
\(m_{HCl}=109,5.10\%=10,95\left(g\right)\Rightarrow n_{HCl}=\dfrac{10,95}{36,5}=0,3\left(mol\right)\)
PTHH: 2Al + 6HCl → 2AlCl3 + 3H2
Mol: 0,1 0,3 0,1 0,15
Ta có: \(\dfrac{0,1}{2}=\dfrac{0,3}{6}\) ⇒ Al hết, HCl hết
\(V_{H_2}=0,15.22,4=3,36\left(l\right)\)
b, \(m_{AlCl_3}=0,1.133,5=13,35\left(g\right)\)
c, mdd sau pứ = 2,7 + 109,5 - 0,15.2 = 111,9 (g)
\(C\%_{ddAlCl_3}=\dfrac{13,35.100\%}{111,9}=11,93\%\)
PTHH: \(2Al+6HCl\rightarrow2AlCl_3+3H_2\uparrow\)
Ta có: \(\left\{{}\begin{matrix}n_{Al}=\dfrac{2,7}{27}=0,1\left(mol\right)\\n_{HCl}=\dfrac{109,5\cdot10\%}{36,5}=0,3\left(mol\right)\end{matrix}\right.\)
Xét tỉ lệ: \(\dfrac{0,1}{2}=\dfrac{0,3}{6}\) \(\Rightarrow\) Al và HCl đều p/ứ hết
\(\Rightarrow\left\{{}\begin{matrix}n_{AlCl_3}=0,1\left(mol\right)\\n_{H_2}=0,15\left(mol\right)\end{matrix}\right.\) \(\Rightarrow\left\{{}\begin{matrix}m_{AlCl_3}=0,1\cdot133,5=13,35\left(g\right)\\V_{H_2}=0,15\cdot22,4=3,36\left(l\right)\\m_{H_2}=0,15\cdot2=0,3\left(g\right)\end{matrix}\right.\)
Mặt khác: \(m_{dd}=m_{Al}+m_{ddHCl}-m_{H_2}=111,9\left(g\right)\)
\(\Rightarrow C\%_{AlCl_3}=\dfrac{13,35}{111,9}\cdot100\%\approx11,93\%\)
PTHH: \(Fe+2HCl\rightarrow FeCl_2+H_2\uparrow\)
a) Ta có: \(n_{Fe}=\dfrac{11,2}{56}=0,2\left(mol\right)=n_{H_2}\) \(\Rightarrow V_{H_2}=0,2\cdot22,4=4,48\left(l\right)\)
b) Theo PTHH: \(n_{HCl}=2n_{Fe}=0,4\left(mol\right)\)
\(\Rightarrow C\%_{HCl}=\dfrac{0,4\cdot36,5}{200}\cdot100\%=7,3\%\)
b) Theo PTHH: \(n_{FeCl_2}=n_{H_2}=0,2\left(mol\right)\) \(\Rightarrow\left\{{}\begin{matrix}m_{FeCl_2}=0,2\cdot127=25,4\left(g\right)\\m_{H_2}=0,2\cdot2=0,4\left(g\right)\end{matrix}\right.\)
Mặt khác: \(m_{dd}=m_{Fe}+m_{ddHCl}-m_{H_2}=210,8\left(g\right)\)
\(\Rightarrow C\%_{FeCl_2}=\dfrac{25,4}{210,8}\cdot100\%\approx12,05\%\)