a. \(PTHH:Mg+2HCl\rightarrow MgCl_2+H_2\uparrow\)

\(n_{Mg}=\dfrac{m_{Mg}}{M_{Mg}}=\dfrac{12}{24}=0,5\left(mol\right)\)

- Mol theo PTHH : \(1:2:1:1\)

- Mol theo phản ứng : \(0,5\rightarrow1\rightarrow0,5\rightarrow0,5\)

\(\Rightarrow n_{H_2}=0,5\left(mol\right)\)

\(\Rightarrow V_{H_2}=n_{H_2}.22,4=0,5.22,4=11,2\left(l\right)\)

b. Từ a. \(\Rightarrow n_{HCl}=1\left(mol\right)\)

\(\Rightarrow m_{HCl}=n_{HCl}.M_{HCl}=1.\left(1+35,5\right)=36,5\left(g\right)\)

c. \(n_{O_2}=\dfrac{V_{O_2}}{22,4}=\dfrac{6,72}{22,4}=0,3\left(mol\right)\)

\(PTHH:2H_2+O_2\underrightarrow{t^o}2H_2O\)

- Mol theo PTHH : \(2:1:2\)

- Mol theo phản ứng : \(0,6\leftarrow0,3\rightarrow0,6\)

\(\Rightarrow n_{H_2O}=0,6\left(mol\right)\)

\(\Rightarrow m_{H_2O}=n_{H_2O}.M_{H_2O}=0,6.\left(2+16\right)=10,8\left(g\right)\)

\(n_{Mg}=\dfrac{3}{24}=0,125mol\)

\(n_{HCl}=\dfrac{10,95}{36,5}=0,3mol\)

\(Mg+2HCl\rightarrow MgCl_2+H_2\)

0,125 <  0,3                              ( mol )

0,125                                   0,125   ( mol )

\(V_{H_2}=0,125.22,4=2,8l\)

Fe + 2HCl -> FeCl2 + H2
nFe = 5,6/56 = 0,1 mol
=>nH2 = 0,1 mol
=> VH2= 0,1*22,4= 2,24 lít

\(n_{Fe}=\dfrac{5,6}{56}=0,1\left(mol\right)\)

PTHH: Fe + 2HCl ---> FeCl₂ + H₂

          0,1-->0,2------------------>0,1

=> \(\left\{{}\begin{matrix}m_{ddHCl}=\dfrac{0,2.36,5}{15\%}=\dfrac{146}{3}\left(g\right)\\V_{H_2}=0,1.22,4=4,48\left(l\right)\end{matrix}\right.\)

\(a.Fe+2HCl\rightarrow FeCl_2+H_2\uparrow\)

b. số mol của 16,8 gam Fe:

\(n_{Fe}=\dfrac{m}{M}=\dfrac{16,8}{56}=0,3\left(mol\right)\)

Khối lượng của HCl:

\(m_{HCl}=n.M=0,6.36,5=21,9\left(g\right)\)

c.Thể tích khí Hiđro (đktc):
\(V_{H_2}=n.22,4=0,3.22,4=6,72\left(l\right)\)

a) Mg + 2HCl → MgCl₂ + H₂

b) nMg =\(\dfrac{14,4}{24}\)=0,6 mol => nH₂ = nMg= 0,6 mol <=> V H₂ = 0,6.22,4 = 13,44 lít

c) nHCl = 2nMg = 1,2mol => mHCl = 1,2.36,5 = 43,8 gam

=> C%_HCl = \(\dfrac{43,8}{200}.100\) =21,9%

nFe = 16,8/56 = 0,3 (mol)

PTHH: Fe + 2HCl -> FeCl2 + H2

Mol: 0,3 ---> 0,6 ---> 0,3 ---> 0,3

VH2 = 0,3 . 24,79 = 7,437 (l)

mHCl = 0,6 . 36,5 = 21,9 (g)

PTHH: CuO + H2 -> (t°) Cu + H2O

Mol: 0,3 <--- 0,3 ---> 0,3

mCu = 0,3 . 64 = 19,2 (g)

mFe = 16,8: 56 =0,3(mol) 
pthh : Fe + 2HCl --> FeCl2 + H2 (1)
         0,3 ->0,6-----------------> 0,3 (mol) 
=> VH2 (đkc) = 0,3 . 24,79 ( l) 
=> mHCl = 0,6 . 35,5 = 21,9 (g) 
pthh : CuO + H2 -t--> Cu+ H2O
           0,3<-----0,3 (mol) 
=>mCu = 0,3 . 64 = 19,2 (g)

 

\(n_{Fe}=\dfrac{16,8}{56}=0,3mol\)

\(Fe+2HCl\rightarrow FeCl_2+H_2\uparrow\)

0,3    0,6          0,3          0,3

\(V_{H_2}=0,3\cdot22,4=6,67l\)

\(m_{HCl}=0,6\cdot36,5=21,9g\)

\(CuO+H_2\rightarrow Cu+H_2O\)

0,3       0,3       0,3

\(m_{Cu}=0,3\cdot64=19,2g\)

a) \(n_{Al}=\dfrac{0,54}{27}=0,02\left(mol\right)\)

PTHH: 2Al + 6HCl --> 2AlCl₃ + 3H₂

_____0,02->0,06---->0,02--->0,03

=> V_H2 = 0,03.22,4 = 0,672 (l)

b) m_HCl = 0,06.36,5 = 2,19 (g)

=> \(C\%_{ddHCl}=\dfrac{2,19}{100}.100\%=2,19\%\)

`a)`

`2Al+6HCl->2AlCl_3+3H_2`

`n_{Al}={0,54}/{27}=0,02(mol)`

`n_{H_2}=3/{2}n_{Al}=0,03(mol)`

`V_{H_2}=0,03.22,4=0,672(l)`

`b)`

`n_{HCl}=2n_{H_2}=0,06(mol)`

`C%_{HCl}={0,06.36,5}/{100}.100%=2,19%`

a, \(Mg+2HCl\rightarrow MgCl_2+H_2\)

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

Theo PT: \(n_{H_2}=n_{Mg}=0,2\left(mol\right)\Rightarrow V_{H_2}=0,2.22,4=4,48\left(l\right)\)

c, \(n_{HCl}=2n_{Mg}=0,4\left(mol\right)\Rightarrow V_{HCl}=\dfrac{0,4}{2}=0,2\left(l\right)=200\left(ml\right)\)

Ta có nH2 = 3,36/22,4 = 0,15 mol
        Fe +2 HCl -> FeCl2 + H2
       0,15.    0,3                   <-. 0,15.  ( Mol)
=> mFe = 0,15 × 56 = 8,4g
   => %Fe = 8,4/15×100% = 56% 
      => %Cu = 100% - 56% = 44%

=>VHCl =1\0,3=10\3 l

PTHH :  2Fe    +     6HCl   -->   2FeCl₃  +  3H₂   (1)

n_H2 =  \(\dfrac{3.36}{22.4}=0.15\left(mol\right)\)

Từ (1) ->  n_Fe = \(\dfrac{2}{3}n_{H_2}=0.1\left(mol\right)\)

-> m_Fe = n.M = 0,1  . 56 = 5.6 (g) => %m_Fe = \(\dfrac{5.6}{15}x100\%\approx37.3\%\)

-> %m_Cu =  100% - 37.3% = 62.7 %