\(n_{H_2}=\frac{2.24}{22.4}=0.1\left(mol\right)\)

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

0.2         0.1         0.1          0.1

\(m_{Fe}=0.1\times56=5.6\left(g\right)\)

\(m_{FeCl_2}=0.1\times127=12.7\left(g\right)\)

\(m_{FeCl_3}=39.4-12.7=26.7\left(g\right)\)

\(n_{FeCl_3}=\frac{26.7}{162.5}=0.16\left(mol\right)\)

\(Fe_2O_3+6HCl\rightarrow2FeCl_3+3H_2O\)

0.08                         0.16 

\(m_{Fe_2O_3}=0.08\times160=12.8\left(g\right)\)

D. 8 lần 

CHO mình 1 like nha bạn

P=\(\sqrt{\frac{\sqrt{x}\left(x\sqrt{x}-1\right)}{x+\sqrt{x}+1}-\frac{\sqrt{x}\left(x\sqrt{x}+1\right)}{x-\sqrt{x}+1}+x+1}\)

  =\(\sqrt{\frac{\sqrt{x}\left(\sqrt{x}-1\right)\left(x+\sqrt{x}+1\right)}{x+\sqrt{x}+1}-\frac{\sqrt{x}\left(\sqrt{x}+1\right)\left(x-\sqrt{x}+1\right)}{x-\sqrt{x}+1}+x+1}\)

  =\(\sqrt{x-\sqrt{x}-x-\sqrt{x}+x+1}\)

  =\(\sqrt{x-2\sqrt{x}+1}\)

  =\(\sqrt{\left(\sqrt{x}-1\right)^2}\)

  =\(\sqrt{x}-1\)

a,Bad organisation spoiled their holiday . 
   Their holiday was spoiled by bad organisation.
b, Teachers mark hundreds of exam papers every year . 
    Hundreds of exam paper are marked by teachers
c, Who wrote Romeo and Juliet? 
    Who had written Romeo and Juliet?
d, You should dry your hair before you go out.
    Your hair should be dried by you before you go out
e, You mustn’t tell him the truth . 
    The truth musn't be told him

Ta có a₁ =\(\sqrt{6}>3\) 

     \(\Rightarrow a_2=\sqrt{6+a_1}< \sqrt{6+3}=3\)

     \(\Rightarrow a_{100}=\sqrt{6+a_{99}}< 3\)

Nên 2<a₁₀₀<3 do đó a₁₀₀ nằm trong khoảng 2

Đơn vị đo đã cho là m3 lun rùi mà sao lại hỏi?
 

\(\sqrt{6}\)