1.

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

PTHH: 2Al + 3H₂SO₄ → Al₂(SO₄)₃ + 3H₂

Mol:      0,3                          0,15          0,45

b, \(V_{H_2}=0,45.22,4=10,08\left(l\right)\)

c, Al₂(SO₄)₃ : nhôm sunfat

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

3.

a, \(n_{Cu}=\dfrac{38,4}{64}=0,6\left(mol\right)\)

PTHH: 2Cu + O₂ ---t^o→ 2CuO

Mol:      0,6     0,3        

CuO: đồng(ll) oxit

b, \(V_{O_2}=0,3.22,4=6,72\left(l\right)\)

c, 

PTHH: 2KMnO₄ ---t^o→ K₂MnO₄ + MnO₂ + O₂

Mol:        0,6                                                 0,3

\(m_{KMnO_4}=0,6.158=47,4\left(g\right)\)

2.

a, \(n_{Zn}=\dfrac{19,5}{65}=0,3\left(mol\right)\)

PTHH: Zn + 2HCl → ZnCl₂ + H₂

Mol:     0,3                   0,3       0,3

b, \(m_{ZnCl_2}=0,3.136=40,8\left(g\right)\)

c, 

PTHH: Fe₂O₃ + 3H₂ ---t^o→ 2Fe + 3H₂O

Mol:      0,1         0,3

\(m_{Fe_2O_3}=0,1.160=16\left(g\right)\)

Câu 1 : 

\(n_{H_2}=\dfrac{2.24}{22.4}=0.1\left(mol\right)\)

\(Zn+H_2SO_4\rightarrow ZnSO_4+H_2\)

\(0.1.....................................0.1\)

\(m_{Zn}=0.1\cdot65=6.5\left(g\right)\)

Câu 2 : 

\(n_{Fe}=\dfrac{11.2}{56}=0.2\left(mol\right)\)

\(n_{HCl}=\dfrac{10.95}{36.5}=0.3\left(mol\right)\)

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

\(1..............2\)

\(0.2...........0.3\)

\(LTL:\dfrac{0.2}{1}>\dfrac{0.3}{2}\Rightarrow Fedư\)

\(m_{Fe\left(dư\right)}=\left(0.2-0.15\right)\cdot56=2.8\left(g\right)\)

\(V_{H_2}=0.15\cdot22.4=3.36\left(l\right)\)

Câu 3 : 

Axit HCl em nhé !

\(n_{HCl}=\dfrac{9.125}{36.5}=0.25\left(mol\right)\)

\(R+2HCl\rightarrow RCl_2+H_2\)

\(0.125..0.25\)

\(M_R=\dfrac{7}{0.125}=56\left(\dfrac{g}{mol}\right)\)

\(R:Fe\left(Sắt\right)\)

\(Zn+H_2SO_4\rightarrow ZnSO_4+H_2\uparrow\\ n_{H_2}=\dfrac{1,12}{22,4}=0,05\left(mol\right)\\ n_{Zn}=n_{H_2SO_4}=n_{H_2}=0,05\left(mol\right)\\ m_{Zn}=0,05.65=3,25\left(g\right)\\ m_{\text{dd}H_2SO_4}=\dfrac{0,05.98}{19,6\%}=25\left(g\right)\\ V_{\text{dd}H_2SO_4}=\dfrac{25}{1,84}\approx13,587\left(ml\right)\)

\(Mg + H_2SO_4 \to MgSO_4 + H_2\\ n_{MgSO_4}= n_{H_2} = n_{H_2SO_4} = n_{Mg} = \dfrac{4,8}{24} = 0,2(mol)\\ \Rightarrow m_{dd\ H_2SO_4} = \dfrac{0,2.98}{19,6\%} = 100(gam)\\ \Rightarrow m_{dd\ sau\ pư} = 4,8 + 100 - 0,2.2 = 104,4(gam)\\ \Rightarrow C\%_{MgSO_4} = \dfrac{0,2.120}{104,4}.100\% = 23\%\)

a) Zn + 2HCl --> ZnCl₂ + H₂

b) \(n_{H_2}=\dfrac{6,1975}{24,79}=0,25\left(mol\right)\)

PTHH: Zn + 2HCl --> ZnCl₂ + H₂

           0,25<-0,5<---0,25<--0,25

=> m_Zn = 0,25.65 = 16,25 (g)

c) m_ZnCl2 = 0,25.136 = 34 (g)

C ?

a) Zn + 2HCl --> ZnCl2 + H2 b) n H 2 = 6 , 1975 24 , 79 = 0 , 25 ( m o l ) PTHH: Zn + 2HCl --> ZnCl2 + H2 0,25<-0,5<---0,25<--0,25 => mZn = 0,25.65 = 16,25 (g) c) mZnCl2 = 0,25.136 = 34 (g)

\(n_{Zn}=\dfrac{6.5}{65}=0.1\left(mol\right)\)

\(Zn+2HCl\rightarrow ZnCl_2+H_2\)

\(0.1.....0.2...........0.1..........0.1\)

\(m_{HCl}=0.2\cdot36.5=7.3\left(g\right)\)

\(m_{\text{dung dịch sau phản ứng}}=6.5+146-0.1\cdot2=152.3\left(g\right)\)

\(C\%_{ZnCl_2}=\dfrac{136\cdot0.1}{152.3}\cdot100\%=8.92\%\)

a) $Zn + 2HCl \to ZnCl_2  + H_2$

b)n Zn = 6,5 /65 = 0,1(mol)

n HCl = 2n Zn = 0,2(mol)

m HCl = 0,2.36,5 = 7,3(gam)

c) n H2 = n Zn = 0,1(mol)

m dd = 6,5 + 146 - 0,1.2 = 152,3(gam) 

C% ZnCl2 = 0,1.136/152,3   .100% = 8,93%

\(n_{CaO}=\dfrac{14}{56}=0,25\left(mol\right)\)

\(m_{ct}=\dfrac{10,95.200}{100}=21,9\left(g\right)\)

\(n_{HCl}=\dfrac{21,9}{36,5}=0,6\left(mol\right)\)

Pt : \(CaO+2HCl\rightarrow CaCl_2+H_2O|\)

          1           2             1            1

         0,25     0,3          0,15

a) Lập tỉ số so sánh : \(\dfrac{0,25}{1}>\dfrac{0,3}{2}\)

                  ⇒ CaO dư , HCl phản ứng hết

                 ⇒ Tính toán dựa vào số mol của HCl

\(n_{CaCl2}=\dfrac{0,3.1}{2}=0,15\left(mol\right)\)

⇒ \(m_{CaCl2}=0,15.111=16,65\left(g\right)\)

b) \(m_{ddspu}=14+200=214\left(g\right)\)

\(C_{CaCl2}=\dfrac{16,65.100}{214}=7,78\)⁰/₀

 Chúc bạn học tốt

\(a,Na_2O+H_2O\rightarrow2NaOH\\ BaO+H_2O\rightarrow Ba\left(OH\right)_2\\ Đặt:n_{Na_2O}=a\left(mol\right);n_{BaO}=b\left(mol\right)\left(a,b>0\right)\\ \Rightarrow\left\{{}\begin{matrix}62a+153b=27,7\\40.2a+171b=33,1\end{matrix}\right.\Leftrightarrow\left\{{}\begin{matrix}a=0,2\\b=0,1\end{matrix}\right.\\ b,\%m_{BaO}=\dfrac{0,1.153}{27,7}.100\approx55,235\%\\ \%m_{Na_2O}\approx100\%-55,235\%\approx44,765\%\\ c,m_{ddbazo}=27,7+200=227,7\left(g\right)\\ C\%_{ddNaOH}=\dfrac{0,2.2.40}{227,7}.100\approx7,027\%\\ C\%_{ddBa\left(OH\right)_2}=\dfrac{0,1.171}{227,7}.100\approx7,51\%\)

a) \(n_{SO_3}=\dfrac{3,2}{80}=0,04\left(mol\right)\)

PTHH: SO₃ + H₂O --> H₂SO₄

          0,04------------->0,04

=> \(m_{H_2SO_4}=0,04.98=3,92\left(g\right)\)

b) \(n_{Na}=\dfrac{0,69}{23}=0,03\left(mol\right)\)

PTHH: 2Na + 2H₂O --> 2NaOH + H₂

            0,03------------>0,03

           2NaOH + H₂SO₄ --> Na₂SO₄ + 2H₂O

Xét tỉ lệ: \(\dfrac{0,03}{2}< \dfrac{0,04}{1}\)=> NaOH hết, H₂SO₄ dư

2NaOH + H₂SO₄ --> Na₂SO₄ + 2H₂O

0,03------>0,015---->0,015

\(\left\{{}\begin{matrix}n_{Na_2SO_4}=0,015\left(mol\right)\\n_{H_2SO_4\left(dư\right)}=0,025\left(mol\right)\end{matrix}\right.\)

=> \(\left\{{}\begin{matrix}m_{Na_2SO_4}=0,015.142=2,13\left(g\right)\\m_{H_2SO_4}=0,025.98=2,45\left(g\right)\end{matrix}\right.\)

c) \(n_{Na}=\dfrac{2,07}{23}=0,09\left(mol\right)\)

PTHH: 2Na + 2H₂O --> 2NaOH + H₂

          0,09-------------->0,09

Xét tỉ lệ: \(\dfrac{0,09}{2}>\dfrac{0,04}{1}\) => NaOH dư, H₂SO₄ hết

2NaOH + H₂SO₄ --> Na₂SO₄ + 2H₂O

0,08<-----0,04------>0,04

=> \(\left\{{}\begin{matrix}n_{NaOH\left(dư\right)}=0,01\left(mol\right)\\n_{Na_2SO_4}=0,04\left(mol\right)\end{matrix}\right.\)

=> \(\left\{{}\begin{matrix}m_{NaOH\left(dư\right)}=0,01.40=0,4\left(g\right)\\m_{Na_2SO_4}=0,04.142=5,68\left(g\right)\end{matrix}\right.\)