\(n_{Zn}=\dfrac{19,5}{65}=0,3\left(mol\right)\\ pthh:Zn+H_2SO_4\rightarrow ZnSO_4+H_2\uparrow\) 
          0,3      0,3                            0,3
\(C\%_{H_2SO_4}=\dfrac{0,3.98}{150}.100\%=19,6\%\) 
\(pthh:Fe_2O_3+3H_2\underrightarrow{t^o}2Fe+3H_2O\) 
                          0,3       0,2 
\(m_{Fe}=0,2.56=11,2\left(g\right)\)
 

Zn+H2SO4->ZnSO4+H2

0,3---0,3--------0,3

3H2+Fe2O3-to>2Fe+3H2O

0,3--------0,1-----------0,2

n Zn=0,3 mol

=>C%=\(\dfrac{0,3.98}{150}100=19,6\%\)

=>m Fe=0,2.56=11,2g

PTHH: \(Fe_2O_3+6HCl\rightarrow2FeCl_3+3H_2O\)

a+b) Ta có: \(n_{Fe_2O_3}=\dfrac{16}{160}=0,1\left(mol\right)\)

\(\Rightarrow\left\{{}\begin{matrix}n_{HCl}=0,6\left(mol\right)\\n_{FeCl_3}=0,2\left(mol\right)\end{matrix}\right.\) \(\Rightarrow\left\{{}\begin{matrix}m_{ddHCl}=\dfrac{0,6\cdot36,5}{14,6\%}=150\left(g\right)\\m_{FeCl_3}=0,2\cdot162,5=32,5\left(g\right)\end{matrix}\right.\)

\(\Rightarrow C\%_{FeCl_3}=\dfrac{32,5}{150+16}\cdot100\%\approx19,58\%\)

b) PTHH: \(HCl+KOH\rightarrow KCl+H_2O\)

Theo PTHH: \(n_{KOH}=n_{HCl}=0,6\left(mol\right)\) \(\Rightarrow V_{KOH}=\dfrac{0,6}{0,5}=1,2\left(l\right)\)

\(Fe_2O_3=\dfrac{24}{160}=0,15\left(mol\right)\\ PTHH:Fe_2O_3+3H_2SO_4\rightarrow Fe_2\left(SO_4\right)_3+3H_2O\\ n_{Fe_2\left(SO_4\right)_3}=n_{Fe_2O_3}=0,15\left(mol\right)\\ a,m_{Fe_2\left(SO_4\right)_3}=400.0,15=60\left(g\right)\\ b,n_{H_2SO_4}=3n_{Fe_2O_3}=3.0,15=0,45\left(mol\right)\\ C_{MddH_2SO_4}=\dfrac{0,45}{0,2}=2,25\left(M\right)\\ c,V_{ddsau}=V_{ddH_2SO_4}=0,2\left(l\right)\\ C_{MddFe_2\left(SO_4\right)_3}=\dfrac{0,15}{0,2}=0,75\left(M\right)\)

a)\(CaSO_3+2HCl\rightarrow CaCl_2+CO_2+H_2O\)

tl 1..................2............1.............1..........1(mol)

br0,125........0,25......0,125........0,125....0,125(mol)

\(m_{CaSO_3}=\dfrac{15}{120}=0,125\left(mol\right)\)

\(\Rightarrow VddHCl=\dfrac{n}{C_M}=\dfrac{0,25}{1}=0,25\left(l\right)\)

\(\Rightarrow C_{MCaCl_2}=\dfrac{0,125}{0,25}=0,5\left(M\right)\)

Bài 2 : 

\(n_{Fe_2O_3}=\dfrac{16}{160}=0,1\left(mol\right)\)

PTHH :

\(Fe_2O_3+3H_2SO_4\rightarrow Fe_2\left(SO_4\right)_3+3H_2O\)

0,1           0,3                 0,1             0,3

\(m_{Fe_2\left(SO_4\right)_3}=0,1.400=40\left(g\right)\)

\(b,V_{ddH_2SO_4}=\dfrac{0,3}{2}=0,15\left(l\right)\)

\(c,C_{M\left(Fe_2\left(SO_4\right)_3\right)}=\dfrac{0,1}{0,15}=\dfrac{2}{3}\left(M\right)\)

Bài 3 :

\(n_{Mg}=\dfrac{4.8}{24}=0,2\left(mol\right)\)

PTHH :

\(Mg+H_2SO_4\rightarrow MgSO_4+H_2O\)

0,2       0,2              0,2          0,2

\(m_{MgSO_4}=0,2.120=24\left(g\right)\)

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

\(c,C_{M\left(H_2SO_4\right)}=\dfrac{0,2}{0,2}=1\left(M\right)\)

\(d,C_{M\left(MgSO_4\right)}=\dfrac{0,2}{0,2}=1\left(M\right)\)

Bài 4 :

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

PTHH :

\(2Al+3H_2SO_4\rightarrow Al_2\left(SO_4\right)_3+3H_2\uparrow\)

0,3       0,45              0,15          0,45

\(V_{H_2}=0,45.24,79=11,1555\left(l\right)\)

\(m_{H_2SO_4}=0,45.98=44,1\left(g\right)\)

\(C\%_{H_2SO_4}=\dfrac{44,1}{300}.100\%=14,7\%\)

\(m_{Al_2\left(SO_4\right)_3}=0,15.342=51,3\left(g\right)\)

\(m_{dd}=8,1+300-\left(0,45.2\right)=307,2\left(g\right)\)

\(C\%_{Al_2\left(SO_4\right)_3}=\dfrac{51,3}{307,2}.100\%\approx16,7\%\)

Bài 5 :

\(n_{H_2}=\dfrac{4,958}{24,79}=0,2\left(mol\right)\)

PTHH:

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

0,2        0,4        0,2       0,2

\(m_{Fe}=0,2.56=11,2\left(g\right)\)

\(C_{M\left(HCl\right)}=\dfrac{0,4}{0,2}=2\left(M\right)\)

\(C_{M\left(FeCl_2\right)}=\dfrac{0,2}{0,2}=1\left(M\right)\)

Bài 6 : 

\(n_{Fe\left(OH\right)_2}=\dfrac{1,8}{90}=0,02\left(mol\right)\)

PTHH :

\(Fe\left(OH\right)_2+2HCl\rightarrow FeCl_2+2H_2O\)

0,02             0,04       0,02          0,04

\(m_{HCl}=0,04.36,5=1,46\left(g\right)\)

\(C\%_{HCl}=\dfrac{1,46}{200}.100\%=0,73\%\)

\(m_{FeCl_2}=0,02.127=2,54\left(g\right)\)

\(C\%_{FeCl_2}=\dfrac{2,54}{1,8+200}\approx1,259\%\)

Bài 7 : 

\(n_{NaOH}=0,1.2=0,2\left(mol\right)\)

PTHH :

\(NaOH+HCl\rightarrow NaCl+H_2O\)

0,2           0,2          0,2          0,2

\(a,m_{NaCl}=0,2.58,5=11,7\left(g\right)\)

\(b,C_{M\left(HCl\right)}=\dfrac{0,2}{0,1}=2\left(M\right)\)

\(c,C_{M\left(NaCl\right)}=\dfrac{0,2}{0,1+0,1}=1\left(M\right)\)

\(a,n_{Fe}=\dfrac{11,2}{56}=0,2(mol)\\ PTHH:Fe+2HCl\to FeCl_2+H_2\\ \Rightarrow n_{HCl}=0,4(mol)\\ \Rightarrow m_{dd_{HCl}}=\dfrac{0,4.36,5}{14,6\%}=100(g)\\ b,n_{H_2}=0,2(mol)\\ \Rightarrow V_{H_2}=0,2.22,4=4,48(l)\\ c,n_{FeCl_2}=0,2(mol)\\ \Rightarrow C\%_{FeCl_2}=\dfrac{0,2.127}{11,2+100-0,2.2}.100\%\approx 22,93\%\)

\(a)n_{Fe}=\dfrac{8,4}{56}=0,15mol\\ Fe+H_2SO_4\rightarrow FeSO_4+H_2\\ n_{H_2}=n_{H_2SO_4}=n_{FeSO_4}=n_{Fe}=0,15mol\\ V=V_{H_2}=0,15.24,79=3,185l\\ b)V_{H_2SO_4}=\dfrac{0,15}{1}=0,15l\\ c)C_{M_A}=C_{M_{FeSO_4}}=\dfrac{0,15}{0,15}=1M\)

Đề thiếu rồi em ơi.

\(a,Fe+H_2SO_4\rightarrow FeSO_4+H_2\\ b,n_{FeSO_4}=n_{H_2SO_4}=n_{H_2}=n_{Fe}=\dfrac{44,8}{56}=0,8\left(mol\right)\\ m_{FeSO_4}=152.0,8=121,6\left(g\right)\\ m_{H_2}=0,8.2=1,6\left(g\right)\\ c,SO_3+H_2O\rightarrow H_2SO_4\\ m_{ddH_2SO_4}=0,8.98:10\%=784\left(g\right)\)