a. \(n_{Fe}=\dfrac{1,8.10^{23}}{6.10^{23}}=0,3\left(mol\right)\)

\(n_{O_2}=\dfrac{6.72}{22,4}=0,3\left(mol\right)\)

PTHH : 3Fe + 2O₂ -> Fe₃O₄

             0,3      0,2        0,1

Ta thấy : \(\dfrac{0.3}{3}< \dfrac{0.3}{2}\) => Fe đủ , O₂ dư

\(m_{Fe_3O_4}=0,1.232=23,2\left(g\right)\)

b. \(V_{O_2}=0,2.22,4=4,48\left(l\right)\)

\(V_{kk}=4,48.5=22,4\left(l\right)\)

a)\(n_{Fe}=\dfrac{1,8\cdot10^{23}}{6\cdot10^{23}}=0,3mol\)

\(n_{O_2}=\dfrac{6,72}{22,4}=0,3mol\)

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

0,3        0,3     0

0,3        0,2      0,1

0           0,1      0,1

\(m_{Fe_3O_4}=0,1\cdot232=23,2g\)

b)\(V_{O_2}=0,1\cdot22,4=2,24l\)

\(\Rightarrow V_{kk}=5V_{O_2}=5\cdot2,24=11,2l\)

a) nFe = 16,8/56 = 0,3 (mol)

PTHH: 3Fe + 2O2 -> (t°) Fe3O4

Mol: 0,3 ---> 0,2 ---> 0,1

mFe3O4 = 0,1 . 232 = 23,2 (g)

b) VO2 = 0,2 . 22,4 = 4,48 (l)

Vkk = 4,48 . 5 = 22,4 (l)

c) H = 100% - 20% = 80%

nO2 (LT) = 0,2 : 80% = 0,25 (mol)

PTHH: 2KMnO4 -> (t°) K2MnO4 + MnO2 + O2

nKMnO4 = 0,25 . 2 = 0,5 (mol)

mKMnO4 = 0,5 . 158 = 79 (g)

a/ PTHH: 4P + 5O2 ===> 2P₂O₅

b/ n_P = 6,2 / 31 = 0,2 mol

=> n_P2O5 = 0,1 mol

=> m_P2O5 = 0,1 x 142 = 14,2 gam

c/ Theo phương trình

=> n_O2 = 0,25 mol

=> V_O2(đktc) = 0,25 x 22,4 = 5,6 lít

\(n_{Al}=\dfrac{2.7}{27}=0.1\left(mol\right)\)

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

\(0.1........0.3............0.1......0.15\)

\(m_{HCl}=0.3\cdot36.5=10.95\left(g\right)\)

\(m_{AlCl_3}=0.1\cdot133.5=13.35\left(g\right)\)

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

Bài 1:

PTHH: \(4Al+3O_2\underrightarrow{t^o}2Al_2O_3\)

Ta có: \(n_{Al}=\dfrac{10,8}{27}=0,4\left(mol\right)\)

\(\Rightarrow\left\{{}\begin{matrix}n_{O_2}=0,3mol\\n_{Al_2O_3}=0,2mol\end{matrix}\right.\) \(\Rightarrow\left\{{}\begin{matrix}V_{O_2}=0.3\cdot22.4=6,72\left(l\right)\\m_{Al_2O_3}=0,2\cdot102=20,4\left(g\right)\end{matrix}\right.\)

Bài 2 : 

\(n_{Na_2O} = \dfrac{12,4}{62} = 0,2(mol)\)

4Na + O₂ \(\xrightarrow{t^o}\) 2Na₂O

0,4......0,1.........0,2..................(mol)

Vậy  :

\(V_{O_2} = 0,1.22,4 = 2,24(lít)\\ m_{Na} = 0,4.23 = 9,2(gam)\)

Bài 1:

a, PT: \(4Al+3O_2\underrightarrow{t^o}2Al_2O_3\)

Ta có: \(n_{Al}=\dfrac{10,8}{27}=0,4\left(mol\right)\)

Theo PT: \(\left\{{}\begin{matrix}n_{O_2}=\dfrac{3}{4}n_{Al}=0,3\left(mol\right)\\n_{Al_2O_3}=\dfrac{1}{2}n_{Al}=0,2\left(mol\right)\end{matrix}\right.\)

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

c, Ta có: \(m_{Al_2O_3}=0,2.102=20,4\left(g\right)\)

Bài 2:

PT: \(4Na+O_2\underrightarrow{t^o}2Na_2O\)

Ta có: \(n_{Na_2O}=\dfrac{12,4}{62}=0,2\left(mol\right)\)

Theo PT: \(\left\{{}\begin{matrix}n_{Na}=2n_{Na_2O}=0,4\left(mol\right)\\n_{O_2}=\dfrac{1}{2}n_{Na_2O}=0,1\left(mol\right)\end{matrix}\right.\)

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

b, Ta cóL \(m_{Na}=0,4.23=9,2\left(g\right)\)

Bạn tham khảo nhé!

a/ PTHH:2Al + 6HCl ===> 2AlCl3 + 3H2

n_Al = 5,4 / 27 = 0,2 mol

=> n_H2 = 0,3 mol

=> m_H2 = 0,3 x 2 = 0,6 gam

=> V_H2(đktc) = 0,3 x 22,4 = 6,72 lít

b/ => n_AlCl3 = 0,3 mol

=> m_AlCl3 = 0,2 x 133,5 = 26,7 gam

muối nhôm clorua là AlCl₃

a)

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

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

\(V_{H_2}=6,72\) ( lít )

\(m_{H_2}=0,6\left(g\right)\)

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

PT: \(4Al+3O_2\underrightarrow{t^o}2Al_2O_3\)

Theo PT: \(n_{O_2}=\dfrac{3}{4}n_{Al}=0,15\left(mol\right)\Rightarrow V_{O_2}=0,15.24,79=3,7185\left(l\right)\)

\(\Rightarrow V_{kk}=\dfrac{V_{O_2}}{20\%}=18,5925\left(l\right)\)

b, Theo PT: \(n_{Al_2O_3}=\dfrac{1}{2}n_{Al}=0,1\left(mol\right)\Rightarrow m_{Al_2O_3}=0,1.102=10,2\left(g\right)\)

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

\(PTHH:4Al+3O_2\underrightarrow{t^o}2Al_2O_3\)

tỉ lệ       :4          3        2

số mol  :0,2       0,15   0,1

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

\(V_{kk}=\dfrac{2,24.20\%}{100\%}=11,2\left(l\right)\)

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

\(a)PTHH:4Al+3O_2\underrightarrow{t^o}2Al_2O_3\)

                       4          3             2

                      0,2      0,15         0,1 (mol)

\(b)m_{Al_2O_3}=n\cdot M=0,1\cdot\left(27\cdot2+16\cdot3\right)=10,2\left(g\right)\\ c)V_{O_2}=n\cdot24,79=0,15\cdot24,79=3,7185\left(l\right).\)

\(n_{Fe}=\dfrac{1,68}{56}=0,03\left(mol\right)\)

\(3Fe+2O_2\rightarrow\left(t^o\right)Fe_3O_4\)

 0,03   0,02               0,01  ( mol )

\(m_{Fe_3O_4}=0,01.232=2,32\left(g\right)\)

\(V_{kk}=0,02.22,4.5=2,24\left(l\right)\)

\(2KClO_3\rightarrow\left(t^o\right)2KCl+3O_2\)

   \(\dfrac{1}{75}\)                               0,02   ( mol )

\(m_{KClO_3}=\dfrac{1}{75}.122,5=1,63\left(g\right)\)

a,nFe=1,68/56=0,03 mol

Ta có PTHH : 3Fe + 2O2 --> Fe3O4 (1) ( ở trên dấu --> có to nha )

Theo PTHH ta có :

nFe3O4=1/3nFe=1/3.0,03=0,01 mol

nO2=2/3nFe=2/3.0,03=0,02 mol

=>mFe3O4= 0,01.232=2,32g

=>Vkk=5.(0,02.22,4)=2,24 l

b, Ta có PTHH: 2KClO3 --> 2KCl + 3O2 (2) ( trên dấu --> vẫn có to )

Gọi x là số mol KClO3 cần dùng ( x > 0 )

Theo PTHH (3) và theo bài ra ta có PTHH sau:

2/3x=0,02 

=> x=0,03 mol

=> mKClO3= 0,03.122,5= 3,675g