a, PT: \(Fe+H_2SO_4\rightarrow FeSO_4+H_2\)

b, Ta có: \(n_{Fe}=\dfrac{19,6}{56}=0,35\left(mol\right)\)

Theo PT: \(n_{H_2}=n_{Fe}=0,35\left(mol\right)\Rightarrow V_{H_2}=0,35.22,4=7,84\left(l\right)\)

c, \(n_{H_2SO_4}=n_{Fe}=0,35\left(mol\right)\Rightarrow C_{M_{H_2SO_4}}=\dfrac{0,35}{0,2}=1,75\left(M\right)\)

d, \(n_{FeSO_4}=n_{Fe}=0,35\left(mol\right)\Rightarrow m_{FeSO_4}=0,35.152=53,2\left(g\right)\)

e, \(C_{M_{FeSO_4}}=\dfrac{0,35}{0,2}=1,75\left(M\right)\)

d, \(n_{H_2SO_4}=0,25.1,6=0,4\left(mol\right)\)

Xét tỉ lệ: \(\dfrac{n_{Fe}}{1}< \dfrac{n_{H_2SO_4}}{1}\), ta được H₂SO₄ dư.

Theo PT: \(n_{H_2SO_4\left(pư\right)}=n_{Fe}=0,35\left(mol\right)\)

\(\Rightarrow n_{H_2SO_4\left(dư\right)}=0,4-0,35=0,05\left(mol\right)\)

\(\Rightarrow m_{H_2SO_4\left(dư\right)}=0,05.98=4,9\left(g\right)\)

a, Ta có:

n_Zn = 13/65= 0,2(mol)

PTHH: Zn + H₂SO₄ → ZnSO₄ + H₂

               _{0,2-----------------------------------0,2}

Theo PT : n_ZnSO4 = 0,2.1/1 = 0,2(mol)

m_ZnSO4 = 0,2. 161 = 32,2(g)

b, Ta có:

Theo PT : n_H2 = 0,2.1/1 = 0,2(mol)

V_H2(đktc) = 0,2 . 22,4 = 4,48(l)

CuO+H2-to>Cu+H2O

           0,2-----0,2

=>m Cu=0,2.64=12,8g

\(n_{Mg}=\dfrac{4,8}{24}=0,2\left(mol\right)\\ pthh:Mg+2HCl\rightarrow MgCl_2+H_2\) 
          0,2       0,4                      0,2  
\(\Rightarrow m_{HCl}=0,4.36,5=14,6\left(g\right)\\ V_{H_2}=0,2.22,4=4,48\left(l\right)\\ pthh:FeO+H_2\underrightarrow{t^o}Fe+H_2O\) 
           0,2      0,2    0,2
\(m_{Fe}=0,2.56=11,2\left(g\right)\)

nMg = 4,8 : 24 = 0,2 mol

a) Mg  +  H₂SO₄  →  MgSO₄  +   H₂

Theo tỉ lệ phản ứng => nH₂SO₄ phản ứng = nMgSO₄ = nH₂ = 0,2 mol

=> VH₂ = 0,2.22,4 = 4,48 lít.

b)

mH₂SO₄ phản ứng = 0,2.98 = 19,6 gam

=> C% _H2SO4 = \(\dfrac{19,6}{300}.100\text{%}\) = 6,53%

c) mMgSO₄ = 0,2.120 = 24 gam.

\(a,n_{Mg}=\dfrac{2,4}{24}=0,1\left(mol\right)\\ PTHH:Mg+H_2SO_4\rightarrow MgSO_4+H_2\uparrow\left(1\right)\\ Theo.pt\left(1\right):n_{H_2}=n_{MgSO_4}=n_{Mg}=0,1\left(mol\right)\\ V_{H_2}=0,1.22,4=2,24\left(l\right)\\ m_{MgSO_4}=0,1.120=12\left(g\right)\\ b,PTHH:CuO+H_2\underrightarrow{t^o}Cu+H_2O\left(2\right)\\ Theo.pt\left(2\right):n_{Cu}=n_{H_2}=0,1\left(mol\right)\\ m_{Cu}=0,1.64=6,4\left(g\right)\)

\(n_{HCl}=0.5\cdot1=0.5\left(mol\right)\)

\(n_{H_2SO_4}=0.5\cdot0.28=0.14\left(mol\right)\)

\(\Rightarrow n_{H^+}=0.5+0.14\cdot2=0.75\left(mol\right)\)

\(n_{H_2}=\dfrac{8.736}{22.4}=0.39\left(mol\right)\)

\(Mg+2H^+\rightarrow Mg^{2+}+H_2\)

\(2Al+6H^+\rightarrow2Al^{3+}+3H_2\)

\(n_{H_2}>2n_{H^+}\)

=> Đề sai 

\(n_{Mg}=\dfrac{12}{24}=0,5\left(mol\right)\\ pthh:Mg+H_2SO_4\rightarrow MgSO_4+H_2\) 
          0,5                          0,5          0,5 
\(m_{MgSO_4}=0,5.120=60g\\ V_{H_2}=0,5.22,4=11,2\left(mol\right)\\ \) 
c) 
\(n_{H_2SO_4}=\dfrac{19,6}{98}=0,2\left(mol\right)\\ pthh:Zn+H_2SO_4\rightarrow ZnSO_4+H_2\\ LTL:0,5>0,2\) 
=> H₂SO₄ dư 
\(n_{Zn\left(p\text{ư}\right)}=n_{H_2SO_4}=0,2\left(mol\right)\\ n_{Zn\left(d\right)}=0,5-0,2=0,3\left(mol\right)\)

\(n_{Al}=\dfrac{8.1}{27}=0.3\left(mol\right)\)

\(n_{H_2SO_4}=\dfrac{29.4}{98}=0.3\left(mol\right)\)

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

\(2.........3\)

\(0.3..........0.3\)

\(LTL:\dfrac{0.3}{2}>\dfrac{0.3}{3}\Rightarrow Aldư\)

\(V_{H_2}=0.3\cdot22.4=6.72\left(l\right)\)

\(m_{Al\left(dư\right)}=\left(0.3-0.2\right)\cdot27=2.7\left(g\right)\)