a) $n_{Mg} = \dfrac{4,8}{24} = 0,2(mol)$
$Mg + 2HCl \to MgCl_2 + H_2$

Theo PTHH : 

$n_{HCl} = 2n_{Mg} = 0,4(mol) \Rightarrow m_{HCl} = 0,4.36,5 = 14,6(gam)$

b)

$n_{MgCl_2} = n_{Mg} = 0,2(mol) \Rightarrow m_{MgCl_2} = 0,2.95 = 19(gam)$

\(n_{Mg}=\dfrac{4,8}{24}=0,2\left(mol\right)\\ Mg+2HCl\rightarrow MgCl_2+H_2\\ 0,2.......0,4........0,2.........0,2\left(mol\right)\\ a.m_{HCl}=0,4.36,5=14,6\left(g\right)\\ b.m_{MgCl_2}=0,2.95=19\left(g\right)\)

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

b) \(n_{Mg}=\dfrac{4,8}{24}=0,2mol\) 

\(n_{HCl}=2.n_{Mg}=0,2.2=0,4mol\)

\(\Rightarrow m_{HCl}=n.M=0,4.36,5=14,6g\)

c) \(n_{H_2}=n_{Mg}=0,2mol\) 

Thể tích khí hidro sinh ra (ở đktc): 

\(V_{H_2}=0,2.24,79=4,958l.\)

a.b.\(n_{Mg}=\dfrac{3,6}{24}=0,15mol\)

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

0,15    0,3                          0,15  ( mol )

\(V_{H_2}=0,15.22,4=3,36l\)

\(m_{HCl}=0,3.36,5=10,95g\)

c.\(n_{H_2}=0,15.60\%=0,09mol\)

\(Ag_2O+H_2\rightarrow\left(t^o\right)2Ag+H_2O\)

            0,09            0,18             ( mol )

\(m_{Ag}=0,18.108=19,44g\)

\(a.n_{Mg}=\dfrac{3,6}{24}=0,15\left(mol\right)\\ Mg+2HCl\rightarrow MgCl_2+H_2\\ TheoPT:n_{H_2}=n_{Mg}=0,15\left(mol\right)\\ \Rightarrow V_{H_2}=0,15.22,4=3,36\left(l\right)\\ b.TheoPT:n_{HCl}=2n_{Mg}=0,3\left(mol\right)\\ \Rightarrow m_{Mg}=0,3.36,5=10,95\left(g\right)\\ c.n_{H_2\left(pứ\right)}=0,15.60\%=0,054\left(g\right)\\ H_2+Ag_2O-^{t^o}\rightarrow2Ag+H_2O\\ n_{Ag}=2n_{H_2}=0,108\left(mol\right)\\ \Rightarrow m_{Ag}=0,108.108=11,664\left(g\right)\)

nMg = 3,6 : 24 = 0,15 (mol) 
pthh : Mg + 2HCl --> MgCl2 + H2 
           0,15-----------> 0,15 --->0,15 (mol) 
mMgCl2 = 0,15 . 95 = 14,25 (mol) 
VH2 (đkc)= 0,15. 24,79 = 3,718(l) 
 

\(n_{Mg}=\dfrac{3,6}{24}=0,15mol\)

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

0,15      0,3         0,15       0,15

\(m_{MgCl_2}=0,15\cdot95=14,25g\)

\(V_{H_2}=0,15\cdot22,4=3,36l\)

\(a.Mg+2HCl\rightarrow MgCl_2+H_2\\ n_{H_2}=\dfrac{44,8}{22,4}=2\left(mol\right)\\ n_{HCl}=2n_{H_2}=4\left(mol\right)\\ \Rightarrow m_{HCl}=4.36,5=146\left(g\right)\\ c.n_{MgCl_2}=n_{H_2}=2\left(mol\right)\\ \Rightarrow m_{MgCl_2}=2.95=190\left(g\right)\)

a.\(n_{Al}=\dfrac{5,4}{27}=0,2\left(mol\right)\)

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

0,2                                     0,3   ( mol )

\(V_{H_2}=0,3.22,4=6,72\left(l\right)\)

b.\(n_{CuO}=\dfrac{48}{80}=0,6\left(mol\right)\)

\(CuO+H_2\rightarrow\left(t^o\right)Cu+H_2O\)

0,6  >  0,3                              ( mol )

          0,3                0,3            ( mol )

\(m_{Cu}=0,3.64=19,2\left(g\right)\)

c.\(2H_2+O_2\rightarrow\left(t^o\right)2H_2O\)

  0,3        0,15                     ( mol )

\(V_{kk}=V_{O_2}.5=\left(0,15.22,4\right).5=16,8\left(l\right)\)

\(n_{Mg}=\dfrac{6}{24}=0,25\left(mol\right)\\ pthh:Mg+H_2SO_4->MgSO_4+H_2\)
          0,25    0,25           0,25            0,25 
\(m_{MgSO_4}=0,25.120=30\left(g\right)\)
\(n_{Fe_2O_3}=\dfrac{24}{160}=0,15\left(mol\right)\\ pthh:Fe_2O_3+3H_2\underrightarrow{t^o}2Fe+3H_2O\)
  LTL : \(\dfrac{0,15}{1}>\dfrac{0,25}{3}\)
=> Fe dư , H2 hết 
=> \(m_{Fe}=\dfrac{1}{6}.56=\approx9,3\left(g\right)\)

a)

 \(PTHH:Mg+2HCl->MgCl_2+H_2\)

               2<------4<----------2<---------2   (mol)

b)

\(n_{H_2\left(dktc\right)}=\dfrac{V}{22,4}=\dfrac{44,8}{22,4}=2\left(mol\right)\)

\(m_{HCl}=n\cdot M=4\cdot\left(1+35,5\right)=146\left(g\right)\)

c)

\(m_{MgCl_2}=n\cdot M=2\cdot\left(24+71\right)=190\left(g\right)\)

\(n_{H_2}=\dfrac{V}{22,4}=\dfrac{44,8}{22,4}=2\left(mol\right)\)

\(\text{a)}Mg+2HCl\rightarrow MgCl_2+H_2\)

             \(2mol\)       \(1mol\)       \(1mol\)

              \(4mol\)       \(2mol\)       \(2mol\)

\(b)m_{HCl}=n.M=4.36,5=146\left(g\right)\)

\(c)m_{MgCl_2}=n.M=2.95=190\left(g\right)\)