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Hiện tượng : kẽm bị tan dần , có khí không màu thoát ra .
Zn + 2HCl ---> ZnCl2 + H2
0,1 0,2 0,1 0,1
nZn = 6,5 / 65 = 0,1 ( mol )
V H2 = \(\dfrac{n.R.t}{p}=\dfrac{0,1.0,082.\left(273+25\right)}{1}=2,4436\left(l\right)\)
H2 + CuO ---> Cu + H2O
0,1 0,1
=> mCu = 0,1 . 64 = 6,4 (g)
nFe = 11,2/56 = 0,2 (mol)
PTHH: Fe + 2HCl -> FeCl2 + H2
Mol: 0,2 ---> 0,4 ---> 0,2 ---> 0,2
VH2 = 0,2 . 22,4 = 4,48 (l)
PTHH: CuO + H2 -> (to) Cu + H2O
Mol: 0,2 <--- 0,2 ---> 0,2
mCu = 0,2 . 64 = 12,8 (g)
a) \(n_{Zn}=\dfrac{9,75}{65}=0,15\left(mol\right)\)
PTHH: Zn + 2HCl --> ZnCl2 + H2
0,15-->0,3------>0,15-->0,15
=> mHCl = 0,3.36,5 = 10,95 (g)
b)
mZnCl2 = 0,15.136 = 20,4 (g)
c)
PTHH: Fe2O3 + 3H2 --to--> 2Fe + 3H2O
0,05<---0,15------->0,1
=> mFe2O3 = 0,05.160 = 8 (g)
mFe = 0,1.56 = 5,6 (g)
a.b.\(n_{Zn}=\dfrac{m_{Zn}}{M_{Zn}}=\dfrac{9,75}{65}=0,15mol\)
\(Zn+2HCl\rightarrow ZnCl_2+H_2\)
0,15 0,3 0,15 0,15 ( mol )
\(m_{HCl}=n_{HCl}.M_{HCl}=0,3.36,5=10,95g\)
\(m_{ZnCl_2}=n_{ZnCl_2}.M_{ZnCl_2}=0,15.136-20,4g\)
c.\(Fe_2O_3+3H_2\rightarrow2Fe+3H_2O\)
0,05 0,15 0,1 ( mol )
\(m_{Fe_2O_3}=n_{Fe_2O_3}.M_{Fe_2O_3}=0,05.160=8g\)
\(m_{Fe}=n_{Fe}.M_{Fe}=0,1.56=5,6g\)
a, \(n_{Zn}=\dfrac{13}{65}=0,2\left(mol\right)\)
PT: \(Zn+2HCl\rightarrow ZnCl_2+H_2\)
_____0,2____0,4___________0,2 (mol)
\(\Rightarrow m_{HCl}=0,4.36,5=14,6\left(g\right)\)
b, \(V_{H_2}=0,2.24,79=4,958\left(l\right)\)
c, \(Fe_2O_3+3H_2\underrightarrow{t^o}2Fe+3H_2O\)
____________0,2__2/15 (mol)
\(\Rightarrow m_{Fe}=\dfrac{2}{15}.56=\dfrac{112}{15}\left(g\right)\)
Số mol của 13 gam Zn:
\(n_{Zn}=\dfrac{m}{M}=\dfrac{13}{65}=0,2\left(mol\right)\)
PTHH: \(Zn+2HCl\rightarrow ZnCl_2+H_2\uparrow\)
1 : 2 : 1 : 1 (g)
0,2\(\rightarrow\) 0,4 : 0,2 : 0,2 (mol)
a,Khối lượng của 0,4 mol HCl:
\(m_{HCl}=n.M=0,4.36,5=14,6\left(g\right)\)
b, Thể tích khí H2:
\(V_{H_2}=n.24,79=0,2.24,79=4,958\left(l\right)\)
\(3H_2+Fe_2O_3\underrightarrow{t^o}2Fe+3H_2O\)
Khối lượng của \(\dfrac{2}{15}\) mol Fe:
\(n_{Fe}=\dfrac{m}{M}=\dfrac{2}{\dfrac{15}{56}}\approx7,5\left(g\right)\)
nMg = 6/24 = 0,25 (mol)
PTHH: Mg + 2HCl -> MgCl2 + H2
nH2 = 0,25 (mol(
VH2 = 0,25 . 24,79 = 6,1975 (l)
CuO + H2 -> (t°) Cu + H2O
nCu = 0,25 (mol)
mCu = 0,25 . 64 = 16 (g)
\(n_{Fe}=\dfrac{m_{Fe}}{M_{Fe}}=\dfrac{8,4}{56}=0,15mol\)
\(Fe+2HCl\rightarrow FeCl_2+H_2\)
0,15 0,3 0,15 0,15 ( mol )
\(V_{H_2}=n_{H_2}.22,4=0,15.22,4=3,36l\)
\(m_{HCl}=n_{HCl}.M_{HCl}=0,3.36,5=10,95g\)
\(m_{FeCl_2}=n_{FeCl_2}.M_{FeCl_2}=0,15.127=19,05g\)
Bài 1:
a, \(n_{Zn}=\dfrac{19,5}{65}=0,3\left(mol\right)\)
PT: \(Zn+2HCl\rightarrow ZnCl_2+H_2\)
Theo PT: \(n_{H_2}=n_{Zn}=0,3\left(mol\right)\Rightarrow V_{H_2}=0,3.24,79=7,437\left(l\right)\)
b, \(n_{Fe_2O_3}=\dfrac{19,2}{160}=0,12\left(mol\right)\)
PT: \(Fe_2O_3+3H_2\underrightarrow{t^o}2Fe+3H_2O\)
Xét tỉ lệ: \(\dfrac{0,12}{1}>\dfrac{0,3}{3}\), ta được Fe2O3 dư.
Theo PT: \(n_{Fe}=\dfrac{2}{3}n_{H_2}=0,2\left(mol\right)\Rightarrow m_{Fe}=0,2.56=11,2\left(g\right)\)
Bài 2:
Ta có: \(n_{Na}=\dfrac{9,2}{23}=0,4\left(mol\right)\)
PT: \(2Na+2H_2O\rightarrow2NaOH+H_2\)
Theo PT: \(n_{H_2}=\dfrac{1}{2}n_{Na}=0,2\left(mol\right)\Rightarrow V_{H_2}=0,2.24,79=4,958\left(l\right)\)
\(n_{NaOH}=n_{Na}=0,4\left(mol\right)\Rightarrow m_{NaOH}=0,4.40=16\left(g\right)\)
\(n_{Mg}=\dfrac{7,2}{24}=0,3\left(mol\right)\)
PTHH:
Mg + 2HCl ---> MgCl2 + H2
0,3-->0,6----------------->0,3
=> \(\left\{{}\begin{matrix}V_{H_2}=24,79.0,3=7,437\left(l\right)\\m_{HCl}=0,6.36,5=21,9\left(g\right)\end{matrix}\right.\)
\(n_{CuO}=\dfrac{12}{80}=0,15\left(mol\right)\)
PTHH: CuO + H2 --to--> Cu + H2O
LTL: 0,15 < 0,3 => H2 dư, vậy H2 khử hết CuO
a, \(n_{Mg}=\dfrac{7,2}{24}=0,3\left(mol\right)\)
Mg + 2HCl -----> MgCl2 + H2
0,3 0,6 0,3
\(V_{H_2}=0,3.22,4=6,72\left(l\right)\)
b, \(m_{HCl}=0,6.36,5=21,9\left(g\right)\)
c, \(n_{CuO}=\dfrac{12}{80}=0,15\left(mol\right)\)
CuO + H2 -----> Cu + H2O
Ta có: \(\dfrac{0,15}{1}< \dfrac{0,3}{1}\) ⇒ CuO hết, H2 dư
a)
\(n_{H_2}=\dfrac{7,437}{24,79}=0,3\left(mol\right)\)
PTHH: 2Al + 6HCl --> 2AlCl3 + 3H2
0,2<---0,6<-----0,2<---0,3
=> mAl = 0,2.27 = 5,4 (g)
mHCl = 0,6.36,5 = 21,9 (g)
b) mAlCl3 = 0,2.133,5 = 26,7 (g)
c)
PTHH: Fe2O3 + 3H2 --to--> 2Fe + 3H2O
0,1<---0,3---------->0,2
=> mFe2O3 = 0,1.160 = 16 (g)
d) mFe = 0,2.56 = 11,2 (g)
a.b.\(n_{H_2}=\dfrac{V_{H_2}}{24,79}=\dfrac{7,437}{24,79}=0,3mol\)
\(2Al+6HCl\rightarrow2AlCl_3+3H_2\)
0,2 0,6 0,2 0,3 ( mol )
\(m_{Al}=n_{Al}.M_{Al}=0,2.27=5,4g\)
\(m_{HCl}=n_{HCl}.M_{HCl}=0,6.36,5=21,9g\)
\(m_{AlCl_3}=n_{AlCl_3}.M_{AlCl_3}=0,2.133,5=26,7g\)
c.d.\(Fe_2O_3+3H_2\rightarrow\left(t^o\right)2Fe+3H_2O\)
0,1 0,3 0,2 ( mol )
\(m_{Fe_2O_3}=n_{Fe_2O_3}.M_{Fe_2O_3}=0,1.160=16g\)
\(m_{Fe}=n_{Fe}.M_{Fe}=0,2.56=11,2g\)
a, \(n_{Zn}=\dfrac{26}{65}=0,4\left(mol\right)\)
\(n_{HCl}=\dfrac{18,25}{36,5}=0,5\left(mol\right)\)
PT: \(Zn+2HCl\rightarrow ZnCl_2+H_2\)
Xét tỉ lệ: \(\dfrac{0,4}{1}>\dfrac{0,5}{2}\), ta được Zn dư.
Theo PT: \(n_{ZnCl_2}=\dfrac{1}{2}n_{HCl}=0,25\left(mol\right)\Rightarrow m_{ZnCl_2}=0,25.136=34\left(g\right)\)
b, \(m_{ddHCl}=\dfrac{18,25}{20\%}=91,25\left(g\right)\)
c, \(n_{H_2}=\dfrac{1}{2}n_{HCl}=0,25\left(mol\right)\)
PT: \(FeO+H_2\underrightarrow{t^o}Fe+H_2O\)
Theo PT: \(n_{FeO}=n_{H_2}=0,25\left(mol\right)\Rightarrow m_{FeO}=0,25.72=18\left(g\right)\)