ủa ủa chất xúc tác là MnO2 chứ đâu phải V2O5

cô mk bảo ghi t^o thoi đc r

Theo đề bài, ta có: \(2Z+N=49\left(1\right)\)

          \(N=53,125\%.2Z\Leftrightarrow1,0625Z-N=0\left(2\right)\)

Từ (1) và (2) \(\Rightarrow\left\{{}\begin{matrix}Z=16\\N=17\end{matrix}\right.\Rightarrow A=Z+N=16+17=33\)

\(\Rightarrow KHNT:^{16}_{33}S\)

a) \(PTHH:4Al+3O_2\underrightarrow{t^o}2Al_2O_3\)

b) Theo định luật bảo toàn khối lượng, ta có:

\(m_{Al}+m_{O_2}=m_{Al_2O_3}\\ \Rightarrow54+m_{O_2}=102\\ \Rightarrow m_{O_2}=102-54=48\left(g\right)\)

\(n_{O_2}=\dfrac{3,36}{22,4}=0,15\left(mol\right)\\ PTHH:2KClO_3\underrightarrow{t^o}2KCl+3O_2\\ \left(mol\right).....0,1..........0,1\leftarrow0,15\\ m_{KClO_3}=0,1.122,5=12,25\left(g\right)\)

1. He’s very intelligent. He knows ________about Maths.

     A. something               B. anything                C. nothing                   D. everything

2. Please speak more slowly, I can’t understand________

     A. something               B. anything                 C. nothing                   D. everything

3. ________, stop talking and listen to me, please!

     A. Everybody             B. Nobody                  C. Anybody                D. Somebody

4. She’s very tired ________becomes boring to her.

     A. Nothing                  B. Something              C. Everything              D. Anything

5. Be quiet! Dad is talking to ________in the living-room.

     A. someone                 B. something               C. everyone                 D. everything

6. There’s ________on my back. Can you have a look at it?

     A. something               B. anything                 C. nothing                   D. everything

7. Let’s go out for dinner. There’s ________ in the fridge.

     A. something               B. anything                 C. nothing                   D. everything

8. Is there ________interesting on T.V now?

     A. something               B. anything                 C. nothing                   D. everything

9. He put ________on his desk a few minutes ago.

     A. somebody               B. something               C. anything                 D. anybody

10. Did you tell her ________about our plans?

                        A. something               B. somebody               C. anything                 D. anybody

8. easier than

9. more comfortable than

10. more interesting

1. cheaper than

2. more effective

3. more beautiful than

4. more powerful than

5. taller than

6. heavier than

7. longer than

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

b) Theo định luật bảo toàn khối lượng, ta có:

\(m_{Al}+m_{H_2SO_4}=m_{Al_2\left(SO_4\right)_3}+m_{H_2}\\ \Rightarrow27+m_{H_2SO_4}=171+3\\ \Rightarrow m_{H_2SO_4}=171+3-27=147\left(g\right)\)

Unless it rained heavily, the match couldn't be cancelled