\(n_K=\dfrac{3,9}{39}=0,1mol\)

\(2K+2H_2O\rightarrow2KOH+H_2\)

0,1      0,1             0,1        0,05  ( mol )

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

\(C_{M_{KOH}}=\dfrac{0,1}{0,2}=0,5M\)

\(m_{H_2O}=0,1.18=1,8g\)

\(n_K=\dfrac{3,9}{39}=0,1\left(mol\right)\\ pthh:K+H_2O\rightarrow KOH+\dfrac{1}{2}H_2\) 
           0,1     0,1        0,1         0,05 
\(V_{H_2}=0,05.22,4=1,12l\\ C_M=\dfrac{0,1}{0,2}=0,5\left(mol\right)\\ m_{H_2O}=0,1.18=1,8g\)

FeCl2 hay FeCl3, ghi cái đề cũng không xong mà đòi người khác giải trong 5 phút: )

:))

Science and technology has become a debated topic in the society. On one hand, it is necessary for the modern life where other countries are continuously developing in the field of science and technology. It becomes very necessary for other countries too to grow in the same way to be strong and well developed other countries for the future safety and security. It is science and technology which helps other weak countries to develop and be strong. We have to take support of science and technology forever to improve the way of life for the betterment of mankind. If we do not take the help of technologies such as computer, internet, electricity, etc we cannot be economically strong in the future and would be backward forever even we cannot survive in such a competitive and technological world.

Advancement in the field of medical, agriculture, education, economy, sports, games, jobs, tourism, etc are the examples of science and technology. All such advancements show us that how both are equally beneficial for our life. We can see a clear difference in our life style while matching the ancient and modern way of life. High level of scientific and technological advancement in the field of medicine has made easy the treatment of various lethal diseases which was earlier not possible. It has helped a lot to the doctors to find effective ways to cure diseases through medicine or operations as well as research vaccines to cure diseases such as cancer, AIDS, diabetes, Alzheimer’s, Leukemia, etc.

bạn ơi bạn lấy từ đâu vậy ạ

Tham khảo 

:) làm thế này thì còn gì môn khtn nữa, mình ko làm được thì để người khác làm

PTHH : 2Al     +     6HCl  --> 2AlCl3   +    3H2 ↑   (1)

n_AlCl3 = \(\dfrac{m}{M}=\dfrac{13,35}{27+35,5.3}=0.1\left(mol\right)\) 

Từ (1) => n_HCl   =   2n_H2  = 0.2 (mol)

=> m_HCl = n.M  =  0.2 x  36.5 = 7.3 (g)

\(PTHH:2Al+6HCl\rightarrow2AlCl_3+3H_2\\ n_{AlCl_3}=\dfrac{m}{M}=\dfrac{13,35}{133,5}=0,1\left(mol\right)\\ Theo.PTHH:n_{HCl}=3.n_{AlCl_3}=3.0,1=0,3\left(mol\right)\\ m_{HCl}=n.M=0,3.36,5=10,95\left(g\right)\)

n Fe=0,5 mol

Fe+H2sO4->FeSO4+H2

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

=>VH2=0,5.22,4=11,2l

b) 2H2+O2-to>2H2O

   0,5-------------------0,5

=>m H2O=0,5.18=9g

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

PTHH : Fe + H₂SO₄ ( loãng ) -> FeSO₄ + H₂

            0,5                                                  0,5

\(V_{H_2}=0,5.22,4=11,2\left(l\right)\)

b. PTHH : 2H₂ + O₂ -> 2H₂O

               0,5                     0,5

\(m_{H_2O}=0,5.18=9\left(g\right)\)

nFe3O4=m/M=4,64/232=0,02(Mol)

         2O2+.   3Fe --->Fe3O4

Mol:  0,04.    0,06.    0,02

 a:  mO2=               n.M=0.04*32=1,28(g)

  mFe=n.M=0,06*56=3,36(g)

b;   2KClO3----> 2KCl.  + 3O2

Mol: 0,03.           0,03.     0,04

mKClO3=n*M=0,03*122,5

   =3,675(g)

Câu 1 :

a) 4Na + O₂ -> 2Na₂O

Tỉ lệ 4:1:2

b) Zn + 2HCl -> ZnCl₂ + H₂

Ti lệ 1:2:1:1

Câu 2 :

a ) Al + CuSO₄ -> Al₂(SO₄)₃ + Cu

x là 2 

y là 3

b) 2Al + 3CuSO₄ -> Al₂(SO₄)₃ + 3Cu