a,\(n_{Fe}=\dfrac{28}{56}=0,5\left(mol\right)\)

PTHH: Fe + 2HCl → FeCl₂ + H₂

Mol:     0,5      1

 ko câu hỏi 

b, Thiếu thể tích ddHCl

\(n_{Fe}=\dfrac{2,8}{56}=0,05\left(mol\right)\\ Fe+2HCl\rightarrow FeCl_2+H_2\\ n_{HCl}=2.0,05=0,1\left(mol\right);n_{H_2}=n_{Fe}=0,05\left(mol\right)\\ a,V_{ddHCl}=\dfrac{0,1}{2}=0,05\left(l\right)=50\left(ml\right)\\ b,V_{H_2\left(đktc\right)}=0,05.22,4=1,12\left(l\right)\)

\(a,n_{Fe}=\dfrac{2,8}{56}=0,05mol\\ PTHH:Fe+2HCl\rightarrow FeCl_2+H_2\)

tỉ lệ:         1            2              1                 1

số mol:    0,05       0,1           0,05           0,05

\(V_{HCl}=0,1:2=0,05l\\ b,V_{H_2\left(đktc\right)}=0,05.22,4=1,12l\)

\(n_{Fe}=\dfrac{2,8}{56}=0,05\left(mol\right)\)

PT :

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

0,05    0,1                       0,05 

\(a,V_{H_2}=0,05.22,4=1,12\left(l\right)\)

\(b,V_{HCl}=\dfrac{n}{C_M}=\dfrac{0,1}{2}=0,05\left(l\right)\)

a) Fe + 2HCl --> FeCl₂ + H₂

b) \(n_{Fe}=\dfrac{22,4}{56}=0,4\left(mol\right)\)

PTHH: Fe + 2HCl --> FeCl₂ + H₂

_____0,4--->0,8------>0,4--->0,4

=> V_H2 = 0,4.22,4 = 8,96(l)

c) m_HCl = 0,8.36,5 = 29,2 (g)

=> \(m_{dd\left(HCl\right)}=\dfrac{29,2.100}{7,3}=400\left(g\right)\)

mdd (sau pư) = 22,4 + 400 - 0,4.2 = 421,6 (g)

=> \(C\%\left(FeCl_2\right)=\dfrac{127.0,4}{421,6}.100\%=12,05\%\)

Cám ơn nhiều ạ

\(a,n_{Fe}=\dfrac{11,2}{56}=0,2mol\\ Fe+2HCl\rightarrow FeCl_2+H_2\\ n_{H_2}=n_{FeCl_2}=n_{Fe}=0,2mol\\ V_{H_2}=0,2.22,4=4,48l\\ b.n_{HCl}=0,2.2=0,4mol\\ a=m_{ddHCl}=\dfrac{0,4.36,5}{14,6}\cdot100=100g\\ c.C_{\%FeCl_2}=\dfrac{0,2.127}{11,2+100-0,2.2}\cdot100=22,92\%\)

Bài 1 xem lại đề phần 2 nhé=)

3.

\(n_{Fe}=\dfrac{2,8}{56}=0,05\left(mol\right)\\ PTHH:\)

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

0,05->0,1---->0,05---->0,05

a. \(V_{HCl}=\dfrac{0,1}{2}=0,05\left(l\right)\)

b. \(V_{H_2}=0,05.22,4=1,12\left(l\right)\)

c. \(CM_{FeCl_2}=\dfrac{0,05}{0,05}=1M\)

`HaNa♬D`

1

\(1.Na_2O+H_2O\rightarrow2NaOH\\ 2.2KClO_3\xrightarrow[]{t^0}2KCl+3O_2\)

KCl ko ra đc AlCl3 nhé

nFe=2,8/56=0,05(mol)

Fe+2HCl→FeCl2+H2

nHCl=2nFe=0,05.2=0,1(mol)

Vdd HCl=0,1/2=0,05(lít)

câu b đâu rồi bạn

\(n_{HCl}=0,3.1=0,3\left(mol\right)\\ NaOH+HCl\rightarrow NaCl+H_2O\\ n_{NaOH}=n_{NaCl}=n_{HCl}=0,3\left(mol\right)\\ V_{\text{dd}NaOH}=V=\dfrac{0,3}{2}=0,15\left(l\right)\\ C_{M\text{dd}A}=C_{M\text{dd}NaCl}=\dfrac{0,3}{0,15+0,3}=\dfrac{2}{3}\left(M\right)\)

a, \(n_{Al}=\dfrac{2,7}{27}=0,1\left(mol\right)\)

 \(m_{HCl}=109,5.10\%=10,95\left(g\right)\Rightarrow n_{HCl}=\dfrac{10,95}{36,5}=0,3\left(mol\right)\)

PTHH: 2Al + 6HCl → 2AlCl₃ + 3H₂

Mol:      0,1      0,3         0,1       0,15

Ta có: \(\dfrac{0,1}{2}=\dfrac{0,3}{6}\) ⇒ Al hết, HCl hết

\(V_{H_2}=0,15.22,4=3,36\left(l\right)\)

b, \(m_{AlCl_3}=0,1.133,5=13,35\left(g\right)\)

c, m_{dd sau pứ} = 2,7 + 109,5 - 0,15.2 = 111,9 (g)

\(C\%_{ddAlCl_3}=\dfrac{13,35.100\%}{111,9}=11,93\%\)

PTHH: \(2Al+6HCl\rightarrow2AlCl_3+3H_2\uparrow\)

Ta có: \(\left\{{}\begin{matrix}n_{Al}=\dfrac{2,7}{27}=0,1\left(mol\right)\\n_{HCl}=\dfrac{109,5\cdot10\%}{36,5}=0,3\left(mol\right)\end{matrix}\right.\)

Xét tỉ lệ: \(\dfrac{0,1}{2}=\dfrac{0,3}{6}\) \(\Rightarrow\) Al và HCl đều p/ứ hết

\(\Rightarrow\left\{{}\begin{matrix}n_{AlCl_3}=0,1\left(mol\right)\\n_{H_2}=0,15\left(mol\right)\end{matrix}\right.\) \(\Rightarrow\left\{{}\begin{matrix}m_{AlCl_3}=0,1\cdot133,5=13,35\left(g\right)\\V_{H_2}=0,15\cdot22,4=3,36\left(l\right)\\m_{H_2}=0,15\cdot2=0,3\left(g\right)\end{matrix}\right.\)

Mặt khác: \(m_{dd}=m_{Al}+m_{ddHCl}-m_{H_2}=111,9\left(g\right)\)

\(\Rightarrow C\%_{AlCl_3}=\dfrac{13,35}{111,9}\cdot100\%\approx11,93\%\)