Đáp án A.

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

vì nhôm pư với clo thep pthh:

2Al+3Cl2$\to$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)

vậy số gam clo cần dùng là 21,3(g)

PT: \(2Al+3Cl_2\underrightarrow{t^o}2AlCl_3\)

Ta có: \(n_{AlCl_3}=\dfrac{26,7}{133,5}=0,2\left(mol\right)\)

Theo PT: \(n_{Cl_2}=\dfrac{3}{2}n_{AlCl_3}=0,3\left(mol\right)\)

\(\Rightarrow m_{Cl_2}=0,3.71=21,3\left(g\right)\)

Bạn tham khảo nhé!

\(2Al + 3Cl_2 \xrightarrow{t^o} 2AlCl_3\\ n_{Cl_2} = \dfrac{3}{2}n_{AlCl_3} = \dfrac{3}{2}.\dfrac{26,7}{133,5} = 0,3(mol)\\ \Rightarrow m_{Cl_2} = 0,3.71 = 21,3(gam)\)

Chọn A.

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:

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

\(a,PTHH:Zn+Cl_2\rightarrow ZnCl_2\)

\(b,n_{Zn}=\dfrac{m}{M}=\dfrac{13}{65}=0,2\left(mol\right)\\ Theo.PTHH:n_{Cl_2}=n_{ZnCl_2}=n_{Zn}=0,2\left(mol\right)\\ a=m_{Cl_2}=n.M=0,4.35,5=14,2\left(g\right)\)

\(b=m_{ZnCl_2}=n.M=0,2.136=27,2\left(g\right)\)

\(c,PTHH:2Al+3Cl_2\rightarrow2AlCl_3\\ Theo.PTHH:n_{Al}=\dfrac{2}{3}.n_{Cl_2}=\dfrac{2}{3}.0,2=\dfrac{2}{15}\left(mol\right)\\ m_{Al}=n.M=\dfrac{2}{15}.27=3,6\left(g\right)\)

\(n_{AlCl_3}=\frac{26,7}{133,5}=0,2\left(mol\right)\)

\(PTHH:2Al+3Cl_2\underrightarrow{t^o}2AlCl_3\)

(mol)___________3_____2___

(mol)___________0,3___0,2__

\(m_{Cl_2}=71.0,3=21,3\left(g\right)\)

nAlCl3=26,7:133,5=0,3(mol)

PTHH:3Cl2+2Al-to->2AlCl3

mol:....3...............2..............2

mol:..0,45.........................0,3

mCl2=0,45.71=31,95g

nAlCl3=26,7:133,5=0,2(mol)

PTHH:3Cl2+2Al-to->2AlCl3

mol:........3....2................2

mol:.......0,3..................0,2

mCl2=0,3.71=21,3g

a. \(n_{Al_2O_3}=\dfrac{10,2}{102}=0,1\left(mol\right)\)

PTHH : Al₂O₃ + 6HCl -> 2AlCl₃ + 3H₂O

              0,1         0,6          0,2                      ( mol )

\(m_{HCl}=0,6.36,5=21,9\left(g\right)\)

\(m_{AlCl_3}=0,2.133,5=26,7\left(g\right)\)

b. 

PTHH : 3O₂ + 4Al -> 2Al₂O₃

              0,15                 0,1         ( mol) 

\(V_{O_2}=0,15.22,4=3,36\left(l\right)\)

a. \(n_{Al_2O_3}=\dfrac{10,2}{102}=0,1\left(mol\right)\)

PTHH : Al₂O₃ + 3HCl -> 2AlCl₃ + 3H₂O

              0,1         0,3          0,2                      ( mol )

\(m_{HCl}=0,3.36,5=10,95\left(g\right)\)

\(m_{AlCl_3}=0,2.133,5=26,7\left(g\right)\)

b. 

PTHH : 3O₂ + 4Al -> 2Al₂O₃

              0,15                 0,1         ( mol) 

\(V_{O_2}=0,15.22,4=3,36\left(l\right)\)