Đáp án A.

đáp án a bạn nhé

vì nhôm pư với clo thep pthh:

2Al+3Cl₂\(\rightarrow\)2AlCl₃(1)

theo pthh(1) và đề bài ta có:nAlCl₃=26,7:133,5=0,2(mol)

nCl₂ =0,2:2\(\times\)3=0,3(mol)

mCl₂=71\(\times\)0,3=21,3(g)

vậ số gam clo cần dùng là 21,3(g)

Câu 1:

\(Mg+Br_2\rightarrow MgBr_2\\ n_{Br_2}=\dfrac{11,2}{160}=0,07\left(mol\right)=n_{Mg}=n_{MgBr_2}\\ a=m_{Mg}=0,07.24=1,68\left(g\right)\\ m_{MgBr_2}=184.0,07=12,88\left(g\right)\)

Mg+Br2->MgBr2

0,07--0,07----0,07

n Br2=\(\dfrac{11,2}{160}\)=0,07 mol

=>m Mg=0,07.24=1,68g

=>m MgBr2=0,07.184=12,88g

Câu 2:

\(n_{Al}=\dfrac{14,58}{27}=0,54\left(mol\right)\\ 2Al+3Cl_2\rightarrow\left(t^o\right)2AlCl_3\\ n_{AlCl_3}=n_{Al}=0,54\left(mol\right)\\ n_{Cl_2}=\dfrac{3}{2}.0,54=0,81\left(mol\right)\\ V_{Cl_2\left(đktc\right)}=0,81.22,4=18,144\left(l\right)\\ m_{AlCl_3}=0,54.133,5=72,09\left(g\right)\)

Đáp án A

Theo bài ra ta có:

56n_Fe + 64n_Cu =15,2

(Khối lượng ban đầu)

Lại có 3n_Fe + 2n_Cu = 0,3.2

(Bảo toàn e)

n_Fe = 0,1; n_Cu = 0,15

 %m_Fe = 36,84%; %m_Cu = 63,16%.

Đáp án C

n_AlCl3 = 26,7: 133,5 = 0,2 mol

Bảo toàn nguyên tố Cl: 2n_Cl2 = 3n_AlCl3

=> n_Cl2 = 1,5n_AlCl3 = 1,5.0,2 = 0,3 mol

\(n_{FeCl_3}=\dfrac{16.25}{162.5}=0.1\left(mol\right)\)

\(Fe+\dfrac{3}{2}Cl_2\underrightarrow{t^0}FeCl_3\)

\(......0.15......0.1\)

\(2KMnO_4+16HCl\rightarrow2KCl+2MnCl_2+5Cl_2+8H_2O\)

\(0.06...............0.48........................................0.15\)

\(m_{KMnO_4}=0.06\cdot158=9.48\left(g\right)\)

\(V_{dd_{HCl}}=\dfrac{0.48}{1}=0.48\left(l\right)=480\left(ml\right)\)

\(2Fe+ 3Cl_2 \xrightarrow{t^o} 2FeCl_3\\ n_{Cl_2} = \dfrac{3}{2}n_{FeCl_3} = \dfrac{3}{2}.\dfrac{16,25}{162,5} = 0,15(mol)\\ 2KMnO_4 + 16HCl \to 2KCl + 2MnCl_2 + 5Cl_2 + 8H_2O\\ n_{KMnO_4} = \dfrac{2}{5}n_{Cl_2} = 0,06(mol)\\ \Rightarrow m_{KMnO_4} = 0,06.158 = 9,48(gam)\\ n_{HCl} = \dfrac{16}{4}n_{Cl_2} = 0,48(mol)\\ \Rightarrow V_{dd\ HCl} = \dfrac{0,48}{1} = 0,48(lít) = 480(ml)\)

\(n_{FeO}=\dfrac{3.2}{72}=\dfrac{2}{45}\left(mol\right)\)

\(FeO+H_2\underrightarrow{^{^{t^0}}}Fe+H_2O\)

\(\dfrac{2}{45}....\dfrac{2}{45}....\dfrac{2}{45}\)

\(V_{H_2}=\dfrac{2}{45}\cdot22.4=1\left(l\right)\)

\(Fe+\dfrac{3}{2}Cl_2\underrightarrow{^{t^0}}FeCl_3\)

\(\dfrac{2}{45}.............\dfrac{2}{45}\)

\(m_{FeCl_3}=\dfrac{2}{45}\cdot162.5=7.22\left(g\right)\)