\(3Fe+2O_2\underrightarrow{t^o}Fe_3O_4\)

\(n_{Fe}=\dfrac{5,6}{56}=0,1mol\)

Theo pt: \(n_{O_2}=\dfrac{2}{3}n_{Fe}=\dfrac{2}{3}\cdot0,1=\dfrac{1}{15}mol\)

\(\Rightarrow V_{O_2}=\dfrac{1}{15}\cdot22,4=1,5l\)

Cũng theo pt: \(n_{Fe_3O_4}=\dfrac{1}{3}\cdot0,1=\dfrac{1}{30}mol\)

\(\Rightarrow m_{Fe_3O_4}=\dfrac{1}{30}\cdot232=7,73g\)

a. \(n_{Fe}=\dfrac{5.6}{56}=0,1\left(mol\right)\)

PTHH : 3Fe + 2O₂ ----t^o----> Fe₃O₄

             0,1       \(\dfrac{0.2}{3}\)                 \(\dfrac{0.1}{3}\)

b. \(V_{O_2}=\dfrac{0.2}{3}.22,4=\dfrac{4.48}{3}\left(l\right)\)

c. \(m_{Fe_3O_4}=\dfrac{0.1}{3}.232=\dfrac{23.2}{3}\left(g\right)\)

D

D

D

A

a

A

hình 1:

áp dụng t/c 3 góc trong tam giác = 180 độ ta có :

\(\widehat{I}+\widehat{H}+\widehat{x}=180^o\)

\(\Rightarrow\widehat{x}=180^o-\left(90+35\right)=55^o\)

hình 2:

áp dụng t/c 3 góc trong tam giác = 180 độ ta có :

\(2\widehat{x}+\widehat{J}=180^o\)

\(\Rightarrow x=\left(180^o-20^o\right):2=80^o\)

help

xong 

mình chết rồi

S + O2 -> (t°) SO2

4P + 5O2 -> (t°) 2P2O5

2KClO3 -> (t°, MnO2) 2KCl + 3O2

4Al + 3O2 -> (t°) 2Al2O3

CH4 + 2O2 -> (t°) CO2 + 2H2O

a. PTHH : S + O₂ -> SO₂

b. PTHH : 4P + 5O₂ -> 2P₂O₅

c. PTHH : 2KClO₃ -> 2KCl + 3O₂

d. PTHH : 4Al + 3O₂ -> 2Al₂O₃

e. PTHH : CH₄ + 2O₂ -> CO₂ + 2H₂O

Câu 2: Lập phương trình hóa học của các phản ứng sau :

a) S+O2 -t độ-> SO2

b) 4 P + 5O2 --t độ->2 P2O5

c)2 KClO3 -t độ--> 2KCl + 3O2.

d)3 Fe + 2O2 -t độ--> Fe3O4.

e) C2H4 + 3O2 -t độ--> 2CO2 + 2H2O.

Bạn vui lòng tách ra chứ nhìn rối lắm.

1. You have to throw the ball into the net when you play ………… (basketball/ football/ tennis/ badminton) 2. My sister often ………… badminton in her free time. (play/plays /playing/ to play) 3. " …………do you do judo?" - "Twice a week." (When/Where/How often/Why) 4. …………draw on the walls and tables, please. (Do/Don't/ Should/Shouldn't) 5. Last summer, I …………fishing with my uncle in the afternoon. (go/went/goes/going) 6. I like watching football matches, but I am not very good …………playing football. (at/in/on/for) 7. We ………… to Ho Chi Minh City for our last summer vacation. (go/went/goed/will go) 8. …………Liz buy a lot of souvenirs for her friends? (Did/Do/Were/Is) 9. John …………return to America last week. (doesn't/ isn't/didn't/ wasn't) 10. Last weekend Phong and Lan …………their grandparents. (visit/is visiting/will visit/visited) 11. All of us …………at home yesterday evening. (were/was/did/are) 12. She …………home at 7;15 this morning. (leaves/leave/is leaving/left) 13. How much money did he give you? He …………me 20 dollars. (give/gives/ is giving/gave) 14. She …………to the countryside with us last week. (didn't come/doesn't come/ didn't come/coming) 15. He ………… so much last night. (drink/ drinks/drinking/ drank)

1. basketball

 2. plays 

3.How often

 4. Don't

5. went

6.  at

7. went

 8. Did

 9.didn't 

10. visited

11. were

 12. left

 13. gave

14. didn't come

15.  drank

1D

2A

3B

4C

5A

6D

7A

Ví dụ về nguồn điện: \(\left\{{}\begin{matrix}pin\\acquy\end{matrix}\right.\)

Mỗi nguồn đều có hai cực: cực dương \(\left(+\right)\) và cực âm \(\left(-\right)\)

Dòng điện đi từ cực dương về cực âm.

Các nguồn mắc nối tiếp nhau.