PTHH: CuO + CO --t^o--> Cu + CO₂

______0,1---------------------->0,1

Fe₂O₃ + 3CO --> 2Fe + 3CO₂

_0,1----------------------->0,3

=> V_CO2 = (0,1+0,3).22,4 = 8,96(l)

=> D

Đáp án : B

CO không phản ứng với MgO => Chất rắn gồm MgO ; Fe : 0,3 mol ; Cu

Chỉ có Fe phản ứng với H₂SO₄ loãng sinh ra khí H₂

=> n_H2 = n_Fe = 0,3 mol => V = 6,72 lit

Chọn A.

Câu 1: \(m_{hh}=0,2\cdot27+0,4\cdot39=21\left(g\right)\)

Câu 2: \(V_{khí}=\left(0,1+0,15\right)\cdot22,4=5,6\left(l\right)\)

Câu 3: \(n_{NO_2}=\dfrac{6,9}{46}=0,15\left(mol\right)\) \(\Rightarrow V_{khí}=\left(0,15+0,15\right)\cdot22,4=6,72\left(l\right)\)

Câu 4: 

Ta có: \(\left\{{}\begin{matrix}n_{CO_2}=\dfrac{0,672}{22,4}=0,03\left(mol\right)\\n_{H_2}=\dfrac{8,96}{22,4}=0,4\left(mol\right)\end{matrix}\right.\) \(\Rightarrow m_{hh}=0,03\cdot44+0,4\cdot2=2,12\left(l\right)\)

\(a.\)

\(m_{hh}=0.12\cdot90+0.15\cdot58=19.5\left(g\right)\)

\(b.\)

\(V_{hh}=\left(0.25+0.1+0.05\right)\cdot22.4=8.96\left(l\right)\)

\(c.\)

\(n_A=\dfrac{10.08}{22.4}=0.45\left(mol\right)\)

\(M_A=23\cdot2=46\left(\dfrac{g}{mol}\right)\)

\(m_A=0.45\cdot46=20.7\left(g\right)\)

\(d.\)

\(n_{hh}=\dfrac{6.72}{22.4}=0.3\left(mol\right)\)

Vì CO₂ : O₂ = 2 : 1 

\(\Rightarrow n_{CO_2}=0.2\left(mol\right),n_{O_2}=0.1\left(mol\right)\)

\(m_{hh}=0.2\cdot44+0.1\cdot32=12\left(g\right)\)

\(\overline{M}=\dfrac{12}{0.3}=40\left(\dfrac{g}{mol}\right)\)

16 nCO2=0,2mol

PTHH: 2CO+O2=>2CO2

         0,2<--0,1<---0,2

=> mO2=0,2.32=6,4g

=> khối lượng Oxi phản ứng với H2 là :

9,6-6,4=3,2g

=> nH2O=3,2:32=0,1mol

PTHH: 2H+O2=>H2O

b)

           0,2<-0,1<-0,2

=> mH2=2.0,2=0,4g

mCO =0,2.28=5,6g

=> m hh=5,6+0,4=6g

CuO+H2-to--->Cu+H2O 

0,6----0,6
nCuO =48/80=0,6 (mol)
==>VH2 =0,6×22,4=13.44(l)

17.

\(n_{Fe}=\dfrac{5,6}{56}=0,1mol\)

\(m_{H_2SO_4}=200.19,6\%=39,2g\)

\(n_{H_2SO_4}=\dfrac{39,2}{98}=0,4mol\)

\(Fe+H_2SO_4\rightarrow FeSO_4+H_2\)

0,1 <   0,4                                 ( mol )

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

\(V_{H_2}=0,1.22,4=2,24l\)

Chất còn dư là H2SO4

\(m_{H_2SO_4\left(dư\right)}=\left(0,4-0,1\right).98=29,4g\)

\(\left\{{}\begin{matrix}m_{FeSO_4}=0,1.152=15,2g\\m_{H_2}=0,1.2=0,2g\end{matrix}\right.\)

\(m_{ddspứ}=5,6+200-0,1.2=205,4g\)

\(\left\{{}\begin{matrix}C\%_{FeSO_4}=\dfrac{15,2}{205,4}.100=7,4\%\\C\%_{H_2}=\dfrac{0,2}{205,4}.100=0,09\%\\C\%_{H_2SO_4\left(dư\right)}=\dfrac{29,4}{205,4}.100=14,31\%\end{matrix}\right.\)

\(n_{Fe}=\dfrac{5,6}{56}=0,1\left(mol\right)\)
\(m_{H_2SO_4}=\dfrac{200.19,6}{100}=39,2\left(g\right)\)
\(n_{H_2SO_4}=\dfrac{39,2}{98}=0,4\left(mol\right)\)
pthh : \(Fe+H_2SO_4->FeSO_4+H_2\)
 LTL: 
\(\dfrac{0,1}{1}< \dfrac{0,4}{1}\)
=> H2SO4 dư 
=> \(n_{H_2}=0,1mol\)
=> \(V_{H_2}=0,1.22,4=2,24\left(L\right)\)
theo pthh :\(n_{H_2SO_4\left(p\text{ư}\right)}=n_{Fe}=0,1\left(mol\right)\)
=> \(n_{H_2SO_4\left(d\right)}=0,4-0,1=0,3\left(mol\right)\)
=> \(m_{H_2SO_4}=98.0,3.29,4\left(g\right)\)
ta có mdd =5,6+39,2 = 44,8 (g)
\(C\%=\dfrac{5,6}{44,8}.100\%=12,55\)

\(V_{SO_2}=0,1.22,4=2,24l\)

\(V_{CO}=0,1.22,4=2,24l\\ V_{N_2}=0,1.22,4=2,24l\)

\(\Rightarrow V_{hh}=2,24.3=6,72l\)

Đáp án đúng : A