PT: \(C+O_2\underrightarrow{t^o}CO_2\)

Ta có: \(n_{O_2}=\dfrac{0,56}{22,4}=0,025\left(mol\right)\)

a, Theo PT: \(n_C=n_{O_2}=0,025\left(mol\right)\)

\(\Rightarrow m_C=0,025.12=0,3\left(g\right)\)

b, Theo PT: \(n_{CO_2}=n_{O_2}=0,025\left(mol\right)\)

\(\Rightarrow V_{CO_2}=0,025.22,4=0,56\left(l\right)\)

3.

- Ta có: m _dd CaCl2 = 43,8 + 156,2 = 200 (g)

Mà: C%_CaCl2 = 11,1%

\(\Rightarrow\dfrac{m_{CaCl_2}}{m_{ddCaCl_2}}=0,111\) \(\Rightarrow m_{CaCl_2}=22,2\left(g\right)\) \(\Rightarrow n_{CaCl_2}=\dfrac{22,2}{111}=0,2\left(mol\right)\)

Có: \(n_{CaCl_2}=n_{CaCl_2.xH_2O}=\dfrac{43,8}{111+18x}=0,2\left(mol\right)\)

⇒ x = 6

Vậy: CTPT cần tìm là CaCl₂.6H₂O

- Ta có: \(n_{Na_2CO_3.xH_2O}=n_{Na_2CO_3}=0,1.0,1=0,01\left(mol\right)\)

\(\Rightarrow\dfrac{2,86}{106+18x}=0,01\)

⇒ x = 10

Vậy: CTPT cần tìm là Na₂CO₃.10H₂O.

\(\left(1\right)2Al+6HCl\rightarrow2AlCl_3+3H_2\)

\(\left(2\right)AlCl_3+3NaOH\rightarrow Al\left(OH\right)_3+3NaCl\)

\(\left(3\right)2Al\left(OH\right)_3\rightarrow Al_2O_3+3H_2O\)

\(\left(4\right)Al_2O_3+6HCl\rightarrow2AlCl_3+3H_2O\)

\(2Fe+3Cl_2\rightarrow\left(t^o\right)2FeCl_3\\ FeCl_3+3KOH\rightarrow Fe\left(OH\right)_3+3KCl\\ 2Fe\left(OH\right)_3\rightarrow\left(t^o\right)Fe_2O_3+3H_2O\\ Fe_2O_3+6HCl\rightarrow2FeCl_3+3H_2O\)

2Fe+3Cl₂→(t^o)2FeCl₃

FeCl₃+3KOH→Fe(OH)3+3KCl₂

Fe(OH)₃→(t^o)Fe₂O₃+3H₂O

Fe₂O₃+6HCl→2FeCl₃+3H₂O

\(n_C=n_{CO_2}=0,4\left(mol\right);n_H=2.n_{H_2O}=2.0,4=0,8\left(mol\right)\\ m_C+m_H=0,4.12+0,8.1=5,6=m_A\)

=> A là hidrocacbon: A chỉ có 2 nguyên tố là C và H

\(a,n_C:n_H=0,4:0,8=1:2\\ \Rightarrow A.có.CTĐG:CH_2\\ b,Đặt.CTTQ:\left(CH_2\right)_a\left(a:nguyên,dương\right)\\ M_{\left(CH_2\right)_a}=28\\ \Leftrightarrow14a=28\\ \Leftrightarrow a=2\\ \Rightarrow CTPT:C_2H_4\)

\(Fe_2O_3+2Al\rightarrow\left(t^o\right)Al_2O_3+2Fe\\ n_{Fe_2O_3}=\dfrac{16}{160}=0,1\left(mol\right)\)

TH1: Nếu p.ứ vừa đủ thì ta có:

\(hh.rắn.X:0,1\left(mol\right)Al_2O_3.và.0,2\left(mol\right)Fe\\ m_X=0,1.10,2+0,2.56=21,4\left(g\right)< 24,1\left(g\right)\)

=> P.ứ có dư. Nên loại TH1

TH2: Khi phản ứng có dư. Nếu dư Al.

\(m_{Al\left(dư\right)}=m-0,2.27=m-5,4\left(g\right)\\m_{Fe}=0,1.2.56=11,2\left(g\right)\\ m_{Al_2O_3}=0,1.102=10,2\left(g\right)\\ m_X=\left(m-5,4\right)+11,2+10,2=24,1\\ \Leftrightarrow m=8,1\left(g\right)\\ \Rightarrow n_{Al\left(dư\right)}=\dfrac{8,1}{27}-0,1=0,2\left(mol\right)\\ -VớiTH2:\\ 2Al_{dư}+6HCl\rightarrow2AlCl_3+3H_2\\ Al_2O_3+6HCl\rightarrow2AlCl_3+3H_2O\\ Fe+2HCl\rightarrow FeCl_2+H_2\\ n_{HCl\left(tổng\right)}=0,2.3+0,1.6+0,2.2=1,6\left(mol\right)\\V_{ddHCl}=\dfrac{1,6}{1}=1,6\left(lít\right)=V \)

- TH3: Nếu Al hết, Fe₂O₃ dư

\(X.có:\dfrac{56m}{27}\left(g\right)Fe;\dfrac{17m}{9}\left(g\right)Al_2O_3;\left(16-\dfrac{80m}{27}\right)\left(g\right)Fe_2O_3\left(dư\right)\\ m_X=24,1=\dfrac{56m}{27}+\dfrac{17m}{9}+\left(16-\dfrac{80m}{27}\right)\\ \Leftrightarrow m=8,1\left(g\right)\\ n_{Al\left(bđ\right)}=0,3\left(mol\right)>n_{Fe_2O_3}\left(LOẠI\right)\)

Vậy: V=1,6(lít)