\(a,n_{Fe}=\dfrac{16,8}{56}=0,3\left(mol\right)\\ 3Fe+2O_2\rightarrow\left(t^o\right)Fe_3O_4\\ b,n_{Fe_3O_4}=\dfrac{n_{Fe}}{3}=\dfrac{0,3}{3}=0,1\left(mol\right)\\ \Rightarrow m_{Fe_3O_4}=232.0,1=23,2\left(g\right)\\ n_{O_2}=\dfrac{2}{3}.n_{Fe}=\dfrac{2}{3}.0,3=0,2\left(mol\right)\\ \Rightarrow V_{O_2\left(đktc\right)}=0,2.22,4=4,48\left(l\right)\)

.iron là sắt mà s cho S nx v?

PTHH : \(S+O_2\xrightarrow[]{t^o}SO_2\)

\(BTKl:\) \(m_S+m_{O2}=m_{SO2}\)

\(\Rightarrow m_{O2}=m_{SO2}-m_S=6,4-3,2=3,2\left(g\right)\)

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

\(a.S+O_2\xrightarrow[]{t^0}SO_2 \)

b. Tỉ lệ 1 : 1 : 1

\(c:BTKL:m_S+m_{O_2}=m_{SO_2}\\ \Rightarrow m_{O_2}=m_{SO_2}-m_S\\ =12,8-6,4\\ =6,4g\)

Bảo toàn KL: \(m_S+m_{O_2}=m_{SO_2}\)

\(\Rightarrow m_{O_2}=96-48=48\left(g\right)\\ \Rightarrow C\)

B . 44 g

a) 2Mg + O₂ --t^o--> 2MgO

b) \(n_{Mg}=\dfrac{18}{24}=0,75\left(mol\right)\)

=> n_MgO = 0,75 (mol)

=> m_MgO = 0,75.40 = 30(g)

c) n_O2 = 0,375 (mol)

=> V_O2 = 0,375.24,79 = 9,29625 (l)

cảm ơn ạ

\(n_S=\dfrac{32}{32}=1mol\\ S+O_2\xrightarrow[]{t^0}SO_2\\ n_{SO_2}=n_S=1mol\\ m_{SO_2\left(lt\right)}=1.64=64g\\ m_{SO_2\left(tt\right)}=64\cdot80:100=51,2g\)

4P+5O2-to>2P2O5

0,2-----0,25----0,1

n P=\(\dfrac{6,2}{31}\)=0,2 mol

=>VO2=0,25.24,79=6,1975l
=>m P2O5=0,1.142=14,2g

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 

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

mình cảm ơn bạn ạ