????????????????????????????

3. has / taken / test / Aretha / any / never / so / she / classes / can't / pass / the / .

ARETHA HAS NEVER TAKEN ANY CLASSES, SO SHE CAN'T PASS THE TEST.

4. wanted / to / they / her / so / before / surprise / they / her / a / gift / the / birthday / gave / day / her /

THEY WANTED TO SURPRISE HER , SO THEY GAVE HER A GIFT BEFORE HER BIRTHDAY DAY.

Ta có :

n_O2 = 13,44 : 22,4 = 0,6 (mol)

PTHH :

2KMnO4(1,2) ----> K2MnO4 + MnO2 + O2(0,6)

=> n_KMnO4 = 0,6 . 2 = 1,2 (mol)

=> m_{KMnO4 (PÚ)} = 1,2 . (39 + 55 + 64) = 189,6 (g)

PTHH :

2KClO3(0,4) ----> 2KCl + 3O2(0,6)

=> n_KClO3 = 0,6 : 3 . 2 = 0,4 (mol)

=> m_KClO3 = 0,4 . (39 + 35,5 + 48) = 49 (g)

Như vậy muốn có 13,44 lít khí O2 (đktc) thì nhiệt phân KClO3 cần khối lượng ít hơn

PTHH :

2H2(0,1) + O2(0,05) ----> 2H2O(0,1)

Theo đề bài ta có :

n_H2O = 1,8 : 18 = 0,1 (mol)

=> n_{H2 (PỨ)} = 0,1 (mol)

=> V_{H2 (đktc)} = 0,1 . 22,4 = 2,24 (lít)

n_{O2 (PỨ)} = 0,05 (mol)

=> V_{O2 (đktc)} = 0,05 . 22,4 = 1,12 (lít)

PTHH :

CaO(0,125) + 2HNO3(0,25) -----> Ca(NO3)2(0,125) + H2O

Ta có :

n_CaO = 7 : 56 = 0,125 (mol)

HNO3 dư

=> n_{HNO3 (PỨ)} = 0,125 . 2 = 0,25 (mol)

=> m_{HNO3 (PỨ)} = 0,25 . (1 + 14 + 48) = 15,75 (g)

n_Ca(NO3)2 = 0,125 (mol)

=> m_Ca(NO3)2 = 0,125 . (40 + 28 + 96) = 20,5 (g)

Vậy .........

các bạn cho xin vài tick đi

PTHH :

Ca(OH)2(0,25) + CO2(0,25) -----> CaCO3 + H2O

Theo đề bài ta có :

n_CO2 = 11 : 44 = 0,25 (mol)

Vậy n_{Ca(OH)2 (cần dùng)} = 0,25 (mol)

=> m_Ca(OH)2 = 0,25 . (40 + 32 + 2) = 18,5 (g)

Vậy khối lượng Ca(OH)2 cần dùng là 18,5 g

Tìm lỗi sai :

1. Your bicycle will is=> be repaired tomorrow.

2. He is excited to=> that he can get the scholarship.

3. The students are being testing=> tested by their teacher.

4. She buys=> BOUGHT him an alarm clock last week.

5. The watch was sell=> SOLD five minutes ago.

6. This window was broken with=> BY Jim.

7. Would you mind to close=> CLOSING the door?

8. I'd want=> LIKE you to drive the children home on your car.

9. It's very nice of Henry to help us by=> WITH the homework.

10. Would you mind to bring=> BRINGING these chairs into the room?

11. The film=> SHE/HE is very interested in it

12. We are going to have our room be=> BỎ BE decorated tomorrow.

13. How long it take=> DOES IT TAKE you to finish your housework?

14. Jack is boring=> BORED because of his boring job.

15.Everybody were=> WAS surprised that he passed the exam

1. There books are ........THICKER............ than those books. (THICK)

2. Miss Thuy is .............RIDING............ her bike to word. (RIDE)

3. AIDS is a ..............DANGEROUS.......... disease. (DANGER)

4. I believe you because I know you are ..............TRUTHFUL.......... (TRUTH)

5. His ambition in life is to be a ....................JOURNALIST.......... (JOURNAL)

1. the students will visit the capital ...............summer

a.on b.in c.at d. from

2. they heard a very strange noise ...............midnight

a. on b.in c.at d. from

3. the result will be better if he .............harder

a. work b.works c.worked d. will work

4. if it .............., we will go to the movies

a.didn't rain b. doesn't rain c. won't rain d. isn't rain

5. it was the most exciting film i ......

a. ever saw b. have ever saw c.have ever seen d. have never seen

6. tom burnt his hand when he...........the dinner

a. cooked b. was cooking c. has cooked d. cooks

7. what ..................you......at thí time two days ago ?

a.did........do b. have .......done c. are ........doing d. were ..........doing

8. when we ........home last night , we saw a strange object in the sky

a.drive b. drove c. were driving d. are driving