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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.
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\(a,M_A=22.M_{H_2}=22.2=44(g/mol)\\ b,n_A=\dfrac{6,1975}{24,79}=0,25(mol)\\ \Rightarrow m_A=0,25.44=11(g)\)
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1.D
8,3 - 7,9 = 0,4g
2.D
MH2= MH x 2= 1x2 = 2đvC
n= m:M= 0,4:2= 0,2 mol
V= n x 22,4 = 0,2 x 22,4 = 4,48l
thấy khí thoát ra nên ta tính ptk của H2
câu 3 mình chưa tính ra bạn đợi mình chút nha
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\(n_{Zn}=\dfrac{8,125}{65}=0,125\left(mol\right)\\
pthh:Zn+2HCl\rightarrow ZnCl_2+H_2\uparrow\)
0,125 0,125 0,125
\(V_{H_2}=0,125.224=2,8\left(l\right)\\
m_{\text{dd}}=8,125+50-0,125.2=57,875\left(g\right)\\
C\%_{ZnCl_2}=\dfrac{0,125.136}{57,875}.100\%=29,374\%\)
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a. Trọng lượng của vật là:
P=10.m= 10.15=150N
Trọng lực có phương thẳng đứng, chiều từ trên xuống dưới.b.
c.Trọng lượng của vật là:
P= 10.m= 10.6=60N
Trọng lượng có phương thẳng, đứng chiều từ trên xuống dưới.
Vì vật đang đứng yên, nên chứng tỏ đã có 2 lực cân bằng tác dụng vào vật. Đó là trọng lực và lực nâng (P = Q)
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\(a,4Na+O_2\underrightarrow{t^o}2Na_2O\\ 3Fe+2O_2\underrightarrow{t^o}Fe_3O_4\)
\(b,Fe_2O_3+3H_2\underrightarrow{t^o}2Fe+3H_2O\\ c,Na+H_2O\rightarrow NaOH+\dfrac{1}{2}H_2\uparrow\\ SO_3+H_2O\rightarrow H_2SO_4\\ d,2KClO_3\xrightarrow[MnO_2]{t^o}2KCl+3O_2\uparrow\)
\(a,4Na+O_2\underrightarrow{t^o}2Na_2O\\ 3Fe+2O_2\underrightarrow{t^o}Fe_3O_4\\ Fe_2O_3+3H_2\underrightarrow{t^o}2Fe+3H_2O\\ \\ Na+H_2O\rightarrow NaOH+\dfrac{1}{2}H_2\\ SO_3+H_2O\rightarrow H_2SO_4\)
\(2KClO_3\xrightarrow[xtMnO_2]{t^o}2KCl+3O_2\)
11/ 2Fe(OH)3 --> Fe2O3 + 3H2O
12/ Fe(OH)3 + 3HCl --> FeCl3 + 3H2O
13/ CaCl2 + 2AgNO3 --> Ca(NO3)2 + 2AgCl
14/ 4P + 5O2 --> 2P2O5
15/ N2O5 + H2O --> 2HNO3
16/ Zn + 2HCl --> ZnCl2 + H2
17/ 2Al + 3CuCl2 --> 2AlCl3 + 3Cu
18/ CO2 + Ca(OH)2 --> CaCO3 + H2O
19/ SO2 + Ba(OH)2 --> BaSO3 + H2O
20/ 2KMnO4 --> K2MnO4 + MnO2 + O2
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