\(S+O_2\underrightarrow{t^o}SO_2\)

\(1:1:1:1\)

\(0,2:0,2:0,2:0,2\left(mol\right)\)

\(n_{SO_2}=\dfrac{V}{24,79}=\dfrac{4,958}{24,79}=0,2\left(mol\right)\)

\(a,m_S=n.M=0,2.32=6,4\left(g\right)\)

\(b,V_{O_2}=n.24,79=0,2.24,79=4,958\left(l\right)\)

làm lại ko để ý có điều kiện=))))

\(n_{SO_2\left(dkc\right)}=\dfrac{V}{24,79}=\dfrac{4,958}{24,79}=0,2\left(mol\right)\)

\(PTHH:S+O_2-^{t^o}>SO_2\)

tỉ lệ        1   :     1     :     1

n(mol)  0,2<--0,2<---0,2

\(m_S=n\cdot M=0,2\cdot32=6,4\left(g\right)\\ V_{O_2\left(dkc\right)}=n\cdot24,79=0,2\cdot24,79=4,958\left(l\right)\)

`2KClO_3->2KCl+3O_2`(to)

0,04-----------0,02-----0,06

`n_(KClO_3)=(4,9)/(122,5)=0,04mol`

=>`V_(O_2)=0,06.24,79=1,4847l`

c)

`4P+5O_2->2P_2O_5`(to)

0,048----0,06 mol

`=>m_P=0,048.31=1,488g`

a. \(n_{KMnO_4}=\dfrac{47.4}{158}=0,3\left(mol\right)\)

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

              0,3                                                      0,15

\(V_{O_2}=0,15.22,4=3,36\left(l\right)\)

b. PTHH : 4Al + 3O₂ -> 2Al₂O₃

               0,2      0,15 

\(m_{Al}=0,2.27=5,4\left(g\right)\)

Câu 1 : 

$n_C = \dfrac{4,8}{12} = 0,4(mol) ; n_{O_2} = \dfrac{7,437}{24,79} = 0,3(mol)$$
$C + O_2 \xrightarrow{t^o} CO_2$

Ta thấy : 

$n_C : 1 > n_{O_2} : 1$ nên C dư

$n_{C\ pư} = n_{O_2} = 0,3(mol) \Rightarrow m_{C\ dư} = (0,4 - 0,3).12 = 1,2(gam)$
$\Rightarorw V_{CO_2} = V_{O_2} = 7,437(lít)$

Câu 2 : 

$n_{Mg} = \dfrac{2,4}{24} = 0,1(mol)$
$n_{Cl_2} = \dfrac{9,916}{24,79} = 0,4(mol)$
$Mg + Cl_2 \xrightarrow{t^o} MgCl_2$
Ta thấy : 

$n_{Mg} : 1 < n_{Cl_2} : 1$ nên $Cl_2$ dư

$n_{Cl_2\ pư} = n_{Mg} = 0,1(mol) \Rightarrow m_{Cl_2\ dư} = (0,4 - 0,1).71 = 21,3(gam)$

$n_{MgCl_2}= n_{Mg} = 0,1(mol) \Rightarrow m_{MgCl_2} = 0,1.95 = 9,5(gam)$

\(n_P=\dfrac{0,62}{31}=0,02\left(mol\right)\\ 4P+5O_2\rightarrow\left(t^o\right)2P_2O_5\\ n_{P_2O_5}=\dfrac{2}{4}.0,02=0,01\left(mol\right);n_{O_2}=\dfrac{5}{4}.0,02=0,025\left(mol\right)\\ V_{O_2\left(đkc\right)}=0,025.24,79=0,61975\left(l\right)\\ m_{P_2O_5}=142.0,01=1,42\left(g\right)\)

\(n_P=\dfrac{m}{M}=\dfrac{0,62}{31}=0,02mol\)

PTHH:  \(4P+5O_2\underrightarrow{t^o}2P_2O_5\)

             4        5         2          ( mol )

           0,02   0,025   0,01       ( mol )

\(V_{O_2}=n_{O_2}.22,4=0,025.22,4=0,56l\)

\(m_{P_2O_5}=n_{P_2O_5}.M_{P_2O_5}=0,01.142=1,42g\)

= 1, 42 

_chúc học tốt_

\(n_S=\dfrac{32}{32}=1\left(mol\right)\)

\(n_{O_2}=\dfrac{11.2}{22.4}=0.5\left(mol\right)\)

\(S+O_2\underrightarrow{^{t^0}}SO_2\)

\(1.....1\)

\(1......0.5\)

\(LTL:\dfrac{1}{1}>\dfrac{0.5}{1}\Rightarrow Sdư\)

\(V_{SO_2}=0.5\cdot22.4=11.2\left(l\right)\)

a) \(n_{SO_2}=\dfrac{6,4}{64}=0,1\left(mol\right)\)

PTHH : S + O₂ - t^o---> SO₂

              0,1  0,1             0,1     ( mol )

b) \(m_S=0,1.32=3,2\left(g\right)\)

\(V_{O_2}=0,1.22,4=2,24\left(l\right)\)

\(n_{Fe_3O_4}=\dfrac{2,32}{232}=0,1\left(mol\right)\)

a)

\(3Fe+2O_2\underrightarrow{t^o}Fe_3O_4\)

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

b)

\(V_{O_2}=0,2.24,79=4,958\left(l\right)\)

c)

\(m_{Fe}=0,3.56=16,8\left(g\right)\)

a) Có chất mới sinh ra

b) Theo ĐLBTKL: m_S + m_O2 = m_SO2

=> m_O2 = 6,4 - 3,2 = 3,2 (g)

c) Xét \(d_{O_2/kk}=\dfrac{32}{29}=1,1\)

=> Khí O₂ nặng hơn không khí 1,1 lần