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Những câu hỏi liên quan
3 tháng 10 2023
2
a) Chất rắn màu đen và xanh lơ tan dần, xuất hiện dung dịch mà xanh lam.
\(CuO+H_2SO_4\rightarrow CuSO_4+H_2O\\ Cu\left(OH\right)_2+H_2SO_4\rightarrow CuSO_4+2H_2O\)
b) Chất rắn màu đỏ nâu tan dần, xuất hiện dung dịch màu vàng nâu.
\(Fe_2O_3+6HCl\rightarrow2FeCl_3+3H_2O\\ Fe\left(OH\right)_3+3HCl\rightarrow FeCl_3+3H_2O\)
c) Dần dần xuất hiện kết tủa trắng.
\(H_2SO_4+Ba\left(OH\right)_2\rightarrow BaSO_4+2H_2O\\ H_2SO_4+BaCl_2\rightarrow BaSO_4+2HCl\\ Ba\left(NO_3\right)_2+H_2SO_4\rightarrow BaSO_4+2HNO_3\\ Na_2SO_4+BaCl_2\rightarrow2NaCl+BaSO_4\\ Na_2SO_4+Ba\left(NO_3\right)_2\rightarrow2NaNO_3+BaSO_4\\ Na_2SO_4+Ba\left(OH\right)_2\rightarrow2NaOH+BaSO_4\)
3 tháng 10 2023
\(3:\\ 1/Fe+2HCl\rightarrow FeCl_2+H_2\\ 2/2H_2SO_4+Cu\xrightarrow[t^0]{đặc}CuSO_4+SO_2+2H_2O\\ 3/Fe_2O_3+6HCl\rightarrow2FeCl_3+3H_2O\\ 4/SO_3+H_2O\rightarrow H_2SO_4\\ 5/Ba\left(NO_3\right)_2+H_2SO_4\rightarrow BaSO_4+2HNO_3\\ 6/H_2SO_4+Ba\left(OH\right)_2\rightarrow BaSO_4+2H_2O\)
8 tháng 12 2021
Tham Khảo:
Dear Anna,
I have received your letter and I feel so glad when knowing that you had passed your examinations with good marks. You want me to tell you about my own family. I got married eight years ago. And now I have two sons, they are very studious, my first son is five years old. His name is Khanh. My second son is 3 years old, his name is khiem. My wife is an accountant, She is 35 years old, her name is Doan. My family lives in a small house in thai nguyen city. At the weekend, my family often goes to visit our parents.
Sometimes, we stay at home and clean the house. Now I am preparing for my master entrance examination.it is very hard for me but I try my best, to pass the exam.
I have told you something about my own family life. How about your family life? Are you ready to let me know about it? I am really excited to hear about it.
Best wishes to you
Hermione
15 tháng 9 2021
\(\dfrac{2}{5}-\left|\dfrac{1}{2}-x\right|=6\)
\(\Leftrightarrow\left|\dfrac{1}{2}-x\right|=\dfrac{2}{5}-6\)
\(\Leftrightarrow\left|\dfrac{1}{2}-x\right|=-\dfrac{28}{5}\)( vô lý do \(\left|\dfrac{1}{2}-x\right|\ge0\forall x\))
Vậy \(x\in\left\{\varnothing\right\}\)
15 tháng 9 2021
\(\Rightarrow\left|\dfrac{1}{2}-x\right|=\dfrac{2}{5}-6=-\dfrac{28}{5}\\ \Rightarrow\left[{}\begin{matrix}\dfrac{1}{2}-x=-\dfrac{28}{5},\forall\dfrac{1}{2}-x\ge0\\\dfrac{1}{2}-x=\dfrac{28}{5},\forall\dfrac{1}{2}-x< 0\end{matrix}\right.\\ \Rightarrow\left[{}\begin{matrix}x=\dfrac{61}{10},\forall x\le\dfrac{1}{2}\left(loại\right)\\x=-\dfrac{51}{10},\forall x>\dfrac{1}{2}\left(loại\right)\end{matrix}\right.\Rightarrow x\in\varnothing\)
DT
Đỗ Thanh Hải
CTVVIP
31 tháng 7 2021
1 Where were you yesterday?
2 I was at school yesterday
3 Were you a doctor 2 years ago?
4 Yes, I was
5 He went to school last Monday
6 What is he doing now?
7 He is studying English now
8 I am going to visit my grandparents this weekend
8 tháng 12 2015
dịch sang tiếng anh hả
mk thử dịch nha
1.A:What do they have in the school festival?
B: They sing and dance
2.A: You often go swimming when?
B: I often go swimming on Sunday
3.A: Now you're listening to music, right?
B: No, I'm reading
đúng thì tick nha
moi nguoi lam 1 viec ne muon lam gi cung dc