\(n_{NaOH}=\dfrac{150.8\%}{40}=0,3\left(mol\right)\)

PTHH:

\(2NaOH+H_2SO_4\rightarrow Na_2SO_4+2H_2O\)

0,3              0,15            0,15         0,3

\(m_{HCl}=0,15.98=14,7\left(g\right)\)

\(m_{ddHCl}=\dfrac{14,7.100}{4,9}=300\left(g\right)\)

\(b,m_{Na_2SO_4}=0,15.142=21,3\left(g\right)\)

\(c,C\%_{Na_2SO_4}=\dfrac{21,3}{150+300}.100\%=4,733\%\)

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

\(2Al+3H_2SO_4\rightarrow Al_2\left(SO_4\right)_3+3H_2\)

0,1       0,15             0 ,05            0,15

a)\(V=0,15\cdot22,4=3,36\left(l\right)\)

b)\(m_{H_2SO_4}=0,15\cdot98=14,7\left(g\right)\)

   \(\Rightarrow m_{ddHCl}=\dfrac{14,7}{9,8}\cdot100=150\left(g\right)\)

c) \(m_{H_2}=0,15\cdot2=0,3\left(g\right)\)

    \(m_{ddsau}=2,7+150-0,3=152,4\left(g\right)\)

    \(m_{Al_2\left(SO_4\right)_3}=0,05\cdot342=17,1\left(g\right)\)

   \(\Rightarrow C\%=\dfrac{17,1}{152,4}\cdot100=11,22\%\)

PTHH: \(2Al+3H_2SO_4\rightarrow Al_2\left(SO_4\right)_3+3H_2\uparrow\)

Ta có: \(\left\{{}\begin{matrix}n_{Al}=\dfrac{4,05}{27}=0,15\left(mol\right)\\n_{H_2SO_4}=\dfrac{294\cdot10\%}{98}=0,3\left(mol\right)\end{matrix}\right.\)

Xét tỉ lệ: \(\dfrac{0,15}{2}< \dfrac{0,3}{3}\) \(\Rightarrow\) Axit còn dư

\(\Rightarrow\left\{{}\begin{matrix}n_{Al_2\left(SO_4\right)_3}=0,075\left(mol\right)=n_{H_2SO_4\left(dư\right)}\\n_{H_2}=0,225\left(mol\right)\end{matrix}\right.\) \(\Rightarrow\left\{{}\begin{matrix}V_{H_2}=0,225\cdot22,4=5,04\left(l\right)\\m_{Al_2\left(SO_4\right)_3}=0,075\cdot342=25,65\left(g\right)\\m_{H_2SO_4\left(dư\right)}=0,075\cdot98=7,35\left(g\right)\\m_{H_2}=0,225\cdot2=0,45\left(g\right)\end{matrix}\right.\)

Mặt khác: \(m_{dd}=m_{Al}+m_{ddH_2SO_4}-m_{H_2}=297,6\left(g\right)\)

\(\Rightarrow\left\{{}\begin{matrix}C\%_{Al_2\left(SO_4\right)_3}=\dfrac{25,65}{297,6}\cdot100\%\approx8,62\%\\C\%_{H_2SO_4\left(dư\right)}=\dfrac{7,35}{297,6}\cdot100\%\approx4,47\%\end{matrix}\right.\)

2Al+3H₂SO₄->Al₂(SO₄)₃+3H₂

            0,1----------\(\dfrac{1}{30}\)-------0,1 mol

n _H2=\(\dfrac{2,24}{22,4}\)=0,1 mol

=>m _Al2(SO4)3=\(\dfrac{1}{30}\).342=11,4g

=>CM _H2SO4=\(\dfrac{0,1}{0,2}\)=0,5 M

giúp em với mn ơi

a)  2Al  +  3H₂SO₄ → Al₂(SO₄)₃   + 3H₂

b) nH₂ =\(\dfrac{26,88}{22,4}\)=1,2 mol 

Theo tỉ lệ phản ứng => nAl phản ứng = \(\dfrac{nH_2.2}{3}\)= 0,8 mol

=> mAl phản ứng = 0,8.27= 21,6 gam

c) nAl₂(SO₄)₃ = 1/2 nAl = 0,4 mol

=> m Al₂(SO₄)₃ = 0,4. 342 = 136,8 gam

a) 

b) mAl=21,6gmAl=21,6g

c) mAl2(SO4)3=136,8gmAl2(SO4)3=136,8g

Giải thích các bước giải:

a) Phương trình hoá học:

b) Số mol  sinh ra sau phản ứng:

nAl=23nH2=23⋅1,2=0,8molnAl=23nH2=23⋅1,2=0,8mol

Khối lượng  tham gia phản ứng:

mAl=nAl.MAl=0,8.27=21,6gmAl=nAl.MAl=0,8.27=21,6g

c) Dựa vào phương trình hóa học ta được:

2Al+6HCl-->2AlCl₃+3H₂

0,3----0,9---------0,3------0,45

=>n _Al=8,1\17=0,3 mol

=>V_H2=0,45.22,4=10,08l

=>m _HCl=0,9.26,5=32,85g

=>m_AlCl3=0,3.133,5=40,05g

C2 :Bảo Toàn khối lượng 

=>m _AlCl3=40,05g

2Al+6HCl-2AlCl3+3H2

0,5-------------0,5-----0,75

nAl=0,5 mol

m muối=0,5.133,5=66,75 g

VH2=0,75.22,4=16,8g

2

C% = 5/50 .100=10%

B nha

a. 2Al + 6HCl -> 2AlCl₃ + 3H₂

b. n_Al = \(\dfrac{8.1}{27}=0,3\left(mol\right)\)=> \(n_{H_2}=\dfrac{3}{2}.0,3=0,45\left(mol\right)\)

\(V_{H_2}=0,45.22,4=10,08\left(mol\right)\)

c. \(n_{HCl}=3n_{Al}=3.0,3=0,9\left(mol\right)=>m_{HCl}=0,9.36,5=32,85\left(g\right)\)

Vậy m = 32,85