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) Mg + 2HCl --> MgCl₂ + H₂

b) \(n_{Mg}=\dfrac{4,8}{24}=0,2\left(mol\right)\)

PTHH: Mg + 2HCl --> MgCl₂ + H₂

            0,2--->0,4-------------->0,2

=> m_HCl = 0,4.36,5 = 14,6 (g)

c) \(V_{H_2}=0,2.22,4=4,48\left(l\right)\)

d) 

PTHH: CuO + H₂ --t^o--> Cu + H₂O

                       0,2------->0,2

=> m_Cu = 0,2.64 = 12,8 (g)

a, \(2Al+6HCl\rightarrow2AlCl_3+3H_2\)

b, \(n_{Al}=\dfrac{8,1}{27}=0,3\left(mol\right)\)

Theo PT: \(n_{H_2}=\dfrac{3}{2}n_{Al}=0,45\left(mol\right)\Rightarrow V_{H_2}=0,45.22,4=10,08\left(l\right)\)

c, Ta có: m _{dd sau pư} = 8,1 + 200 - 0,45.2 = 207,2 (g)

Theo PT: \(n_{AlCl_3}=n_{Al}=0,3\left(mol\right)\)

\(\Rightarrow C\%_{AlCl_3}=\dfrac{0,3.133,5}{207,2}.100\%\approx19,33\%\)

\(n_{Al}=\dfrac{6,75}{27}=0,25\left(mol\right)\)

PTHH :

\(2Al+6HCl\rightarrow2AlCl_3+3H_2\uparrow\)

0,25    0,75      0,25          0,375 

\(a,V_{H_2}=0,375.22,4=8,4\left(l\right)\)

\(b,m_{HCl}=0,75.36,5=27,375\left(g\right)\)

\(m_{ddHCl}=\dfrac{27,375.100}{10,95}=250\left(g\right)\)

\(c,m_{AlCl_3}=0,25.133,5=33,375\left(g\right)\)

\(m_{ddAlCl_3}=6,75+250-\left(0,375.2\right)=256\left(g\right)\)

\(C\%_{AlCl_3}=\dfrac{33,375}{256}.100\%\approx13,04\left(\%\right)\)

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`

a) Gọi Kl cần tìm là X có hóa trị chưa biết là n

2X+ 2nHCl = 2XCl_n+ nH₂

Có n_H2=0,25 mol --> n_X= 0,5/n mol ---> m_X=0,5.M_X/n=16,25 --> M_X=32,5n

n=1 => M_X=32,5( không có Kl nào tm)

n=2 => M_X=65( Zn)

b) n_HCl= 2n_H2=2.0,25=0,5 mol

==> VddHCl cần = 0,5/0,2=2,5 lit

a)V khí H2=3,36

b)m dd=100g

c)C%FeCl2=17,57%

\(n\)Fe = \(\dfrac{8,4}{56}\)= 0,15 mol

Fe + 2HCl -----> FeCl\(2\)+H\(2\)

0,15->0,3 ->0,15 -> 0,15 (mol

V\(H2\) = 0,15 . 22,4 = 3,36 l

b, m_{ct HCl} = 0,3 . 36,5 = 10,95 (g)

m_{dd HCl} = \(\dfrac{10,95}{10,95\%}\) = 100 (g)

c, m_{dd sau pu} = 8,4 + 100 - 0,15.2 = 108,1 g

C_{% FeCl2} = \(\dfrac{0,15.127}{108,1}.100\%\)= 1,76%

n_Fe = \(\dfrac{8,4}{56}\) = 0,15 mol

Fe + 2HCl -> FeCl₂ + H₂

1mol 2mol 1mol 1mol

0,15mol 0,3mol 0,15mol 0,15mol

a) V_H2(đktc) = 0,15. 22,4 =3,36 (l)

b) m_HCl = 0,3 . 36,5 = 10,95 (g)

m_ddHCl = \(\dfrac{mct.100\text{%}}{C\%}\) = \(\dfrac{10,95.100\%}{10,95\%}\)

= 100(g)

c) m_FeCl2 = 127 . 0,15 = 19,05 (g)

m_H2 = 0,15 . 2 = 0,3 (g)

m_dd = (100 + 8,4) - 0,3 =108,1 (g)

C% _FeCl2 = \(\dfrac{mct}{mdd}\) . 100% = \(\dfrac{19,05}{108,1}\) . 100%

= 17,62 %

\(n\) \(Zn\) \(=\frac{6,5}{65}=0,1\left(mol\right)\) 
Ta có: 
\(Zn+2HCL\rightarrow ZnCL2+H2\)
\(0,1\rightarrow0,1\rightarrow0,1\)
a) \(V\) \(H2\)\(=22,4.0,1=2,24\left(g\right)\)) 
b) Ta có : 
m dd s.p.ư = m Zn + m dd HCl - m H2 
= 6,5 + 200 - 22,4 * 0,1 
= 204,26 (g) 
m ZnCl2 = 136 * 0,1 = 13,6 (g) 
=> C% ZnCl2 = 13,6 / 204,26 * 100 = ~6,66%

n Zn = 6,5 / 65 = 0,1 (mol) 
Ta có: 
Zn + 2HCl -> ZnCl2 + H2 
0,1 -> 0,1 -> 0,1 
a) V H2 = 22,4 * 0,1 = 2,24 (g) 
b) Ta có : 
m dd s.p.ư = m Zn + m dd HCl - m H2 
= 6,5 + 200 - 22,4 * 0,1 
= 204,26 (g) 
m ZnCl2 = 136 * 0,1 = 13,6 (g) 
=> C% ZnCl2 = 13,6 / 204,26 * 100 = ~6,66%

a, \(n_{Fe}=\dfrac{84}{56}=1,5\left(mol\right)\)

PT: \(Fe+2HCl\rightarrow FeCl_2+H_2\)

Theo PT: \(n_{H_2}=n_{Fe}=1,5\left(mol\right)\Rightarrow V_{H_2}=1,5.22,4=33,6\left(l\right)\)

b, \(n_{HCl}=2n_{Fe}=3\left(mol\right)\Rightarrow m_{HCl}=3.36,5=109,5\left(g\right)\)

\(\Rightarrow m_{ddHCl}=\dfrac{109,5}{10,95\%}=1000\left(g\right)\)

c, \(n_{FeCl_2}=n_{Fe}=1,5\left(mol\right)\)

Ta có: m _{dd sau pư} = 84 + 1000 - 1,5.2 = 1081 (g)

\(\Rightarrow C\%_{FeCl_2}=\dfrac{1,5.127}{1081}.100\%\approx17,62\%\)