Bài 6:

a) \(n_{O_2\left(tt\right)}=\dfrac{2,88}{24}=0,12\left(mol\right)\)

=> \(n_{O_2\left(PTHH\right)}=\dfrac{0,12.100}{80}=0,15\left(mol\right)\)

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

              0,3<--------------------------------0,15

=> \(m_{KMnO_4}=0,3.158=47,4\left(g\right)\)

b) \(n_{KClO_3}=\dfrac{2,45}{122,5}=0,02\left(mol\right)\)

\(V_{O_2\left(tt\right)}=8.0,072=0,576\left(l\right)\)

=> \(n_{O_2\left(tt\right)}=\dfrac{0,576}{24}=0,024\left(mol\right)\)

PTHH: 2KClO₃ --t^o--> 2KCl + 3O₂

               0,02---------------->0,03

=> n_{O2(hao hụt)} = 0,03 - 0,024 = 0,006 (mol)

=> %O₂ bị hao hụt = \(\dfrac{0,006}{0,03}.100\%=20\%\)

Câu 2:

\(4Al+3O2-->2Al2O3\)

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

n\(_{O2}=\frac{6,72}{22,4}=0,3\left(mol\right)\)

\(n_{Al}\left(\frac{0,2}{4}\right)< nO2\left(\frac{0,3}{3}\right)\Rightarrow O2dư\)

n\(_{O2}=\frac{3}{4}n_{Al}=0,15\left(mol\right)\)

\(n_{O2}dư=0,3-0,15=0,15\left(mol\right)\)

m\(_{O2}dư=0,15.32=4,8\left(g\right)\)

b) \(n_{Al2O3}=\frac{1}{2}n_{Al}=0,15\left(mol\right)\)

\(m_{Al2O3}=0,15.102=15,3\left(g\right)\)

a, PT: \(3Fe+2O_2\underrightarrow{t^o}Fe_3O_4\)

Ta có: \(n_{Fe_3O_4}=\dfrac{4,64}{232}=0,02\left(mol\right)\)

Theo PT: \(\left\{{}\begin{matrix}n_{Fe}=3n_{Fe_3O_4}=0,06\left(mol\right)\\n_{O_2}=2n_{Fe_3O_4}=0,04\left(mol\right)\end{matrix}\right.\)

\(\Rightarrow m_{Fe}=0,06.56=3,36\left(g\right)\)

\(m_{O_2}=0,04.32=1,28\left(g\right)\)

b, Phần này đề bài cho là KMnO₄ hay KClO₃ vậy bạn?

a) 

nFe3O4 = 4.64/232 = 0.02 (mol) 

3Fe + 2O2 -to-> Fe3O4 

0.06__0.04______0.02 

mFe = 0.06*56 = 3.36 (g) 

Ủa kali pemanganat là KMnO4 mà ta ? 

2KMnO4 -to-> K2MnO4 + MnO2 + O2 

0.08_________________________0.04 

mKMnO4 = 0.08*158 = 12.64 (g) 

\(V_{O_2\left(thu.được\right)}=28=0,1=2,8\left(l\right)\)

=> \(V_{O_2\left(sinh.ra\right)}=\dfrac{2,8.100}{80}=3,5\left(l\right)\)

=> \(n_{O_2\left(sinh.ra\right)}=\dfrac{3,5}{22,4}=0,15625\left(mol\right)\)

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

           0,3125<------------------------0,15625

=> m_KMnO4 = 0,3125.158 = 49,375 (g)

a.\(n_{KClO_3}=\dfrac{m_{KClO_3}}{M_{KClO_3}}=\dfrac{12,25}{122,5}=0,1mol\)

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

    2                       2           3       ( mol )

  0,1                                 0,15

\(V_{O_2}=n_{O_2}.22,4=0,15.22,4=3,36l\)

b.\(V_{kk}=V_{O_2}.5=3,36.5=16,8l\)

c.\(n_{Fe}=\dfrac{m_{Fe}}{M_{Fe}}=\dfrac{28}{56}=0,5mol\)

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

  3        2                   1         ( mol )

0,5   >   0,15                          ( mol )

0,225              0,15                 ( mol )

\(m_{Fe\left(du\right)}=n_{Fe\left(du\right)}.M_{Fe}=\left(0,5-0,225\right).56=15,4g\)

Cập nhật lại câu hỏi đi bạn :v

\(n_{Al}=\dfrac{5.4}{27}=0,2mol\)

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

0,2     0,15     0,1

a)\(V_{O_2}=0,15\cdot22,4=3,36l\)

b)\(n_{O_2}=0,15\cdot10\%=0,015mol\)

\(2KMnO_4\underrightarrow{t^o}K_2MnO_4+MnO_2+O_2\)

0,03                                               0,015

\(m_{KMnO_4}=0,03\cdot158=4,74g\)