a. PTHH: \(KMnO_4\rightarrow^{t^o}K_2MnO_4+MnO_2+O_2\uparrow\)

b. \(H=100\%\)

\(n_{KMnO_4}=\frac{3,6}{158}=0,023mol\)

Theo phương trình \(n_{O_2}=0,5n_{KMnO_4}=0,046mol\)

\(\rightarrow V_{O_2}=0,0115.22,4.100\%=0,2576l\)

c. H = 80%

\(\rightarrow V_{O_2}=0,0115.22,4.80\%=0,20608l\)

D
B

D

B

D-B

\(n_{O_2}=\dfrac{11,2}{22,4}=0,5\left(mol\right)\)

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

               1<------------------------------------0,5

=> \(m_{KMnO_4\left(pthh\right)}=1.158=158\left(g\right)\)

=> \(m_{KMnO_4\left(tt\right)}=\dfrac{158.100}{80}=197,5\left(g\right)\)

2KMnO₄-to>K₂MnO₄+MnO₂+O₂

0,6------------------------------------0,3 mol

n _O2=\(\dfrac{6,72}{22,4}\)=0,3 mol

=>m _KMnO4pứ=0,6.158.\(\dfrac{100}{90}\)=105,33g

\(m_{KClO_3\left(pư\right)}=\dfrac{15.90}{100}=13,5\left(g\right)\)

=> \(n_{KClO_3\left(pư\right)}=\dfrac{13,5}{122,5}=\dfrac{27}{245}\left(mol\right)\)

PTHH: 2KClO₃ --t^o--> 2KCl + 3O₂

            \(\dfrac{27}{245}\)----------------->\(\dfrac{81}{490}\)

=> \(V_{O_2}=\dfrac{81}{490}.22,4=\dfrac{648}{175}\left(l\right)\)

\(n_{KClO_3}=\dfrac{m_{KClO_3}}{M_{KClO_3}}=\dfrac{15}{122,5}=\dfrac{6}{49}mol\)

\(n_{KClO_3}=\dfrac{6}{49}:90\%=\dfrac{20}{147}mol\)

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

 20/147                          10/49   ( mol )

\(V_{O_2}=n_{O_2}.22,4=\dfrac{10}{49}.22,4=4,5714l\)

a) $2KMnO_4 \xrightarrow{t^o} K_2MnO_4 + MnO_2 + O_2$

b) n KMnO4 = 15,8/158 = 0,1(mol)

Theo PTHH : n O2 = 1/2 n KMnO4 = 0,05(mol)

=> V O2 = 0,05.22,4 = 1,12(lít)

c)

$3Fe + 2O_2 \xrightarrow{t^o} Fe_3O_4$

Theo PTHH : n Fe = 3/2 nO2 = 0,075(mol)

=> m Fe = 0,075.56 = 4,2(gam)

Theo gt ta có: $n_{KMnO_4}=0,1(mol)$

a, $2KMnO_4\rightarrow K_2MnO_4+MnO_2+O_2$

b, Ta có: $n_{O_2}=0,05(mol)\Rightarrow V_{O_2}=1,12(mol)$

c, $3Fe+2O_2\rightarrow Fe_3O_4$

Ta có: $n_{Fe}=0,075(mol)\Rightarrow m_{Fe}=4,2(g)$

   Theo định luật bảo toàn khối lượng ta có: m O 2  = 15,8 – 12,6 = 3,2(g)

   Hiệu suất của phản ứng phân hủy: H = 2,8/3,2 x 100 = 87,5%