\(n_{Fe}=\dfrac{11.2}{56}=0.2\left(mol\right)\)

\(Fe+2HCl\rightarrow FeCl_2+H_2\)

\(0.2.......0.4....................0.2\)

\(V_{H_2}=0.2\cdot22.4=4.48\left(l\right)\)

\(m_{HCl}=0.4\cdot36.5=14.6\left(g\right)\)

3.D

4.C

\(n_{hh}=\dfrac{4.48}{22.4}=0.2\left(mol\right)\)

\(n_{C_2H_4}=75\%\cdot0.2=0.15\left(mol\right)\)

\(\Rightarrow n_{C_4H_8}=0.2-0.15=0.05\left(mol\right)\)

\(C_2H_4+3O_2\underrightarrow{^{^{t^0}}}2CO_2+2H_2O\)

\(C_4H_8+6O_2\underrightarrow{^{^{t^0}}}4CO_2+4H_2O\)

\(V_{O_2}=\left(0.15\cdot3+0.05\cdot6\right)\cdot22.4=16.8\left(l\right)\)

\(V_{CO_2}=\left(0.15\cdot2+0.05\cdot4\right)\cdot22.4=11.2\left(l\right)\)

\(P=10m=2\cdot10=20\left(N\right)\)

D.cả 3 đáp án trên

2.C

1.D

\(n_{Fe}=\dfrac{12.6}{56}=0.225\left(mol\right)\)

\(n_{O_2}=\dfrac{4.2}{22.4}=0.1875\left(mol\right)\)

\(3Fe+2O_2\underrightarrow{^{^{t^0}}}Fe_3O_4\)

\(3.........2\)

\(0.225......0.1875\)

Lập tỉ lệ : \(\dfrac{0.225}{3}< \dfrac{0.1875}{2}\Rightarrow O_2dư\)

\(m_{O_2\left(dư\right)}=\left(0.1875-0.225\cdot\dfrac{2}{3}\right)\cdot32=1.2\left(g\right)\)

\(m_{Fe_3O_4}=\dfrac{0.225}{3}\cdot232=17.4\left(g\right)\)

D. David felt sick because he had eaten too many green apples.

D