\(n_{Al}=\dfrac{6,48}{27}=0,24\left(mol\right)\)

\(n_{Fe_2O_3}=\dfrac{17,6}{160}=0,11\left(mol\right)\)

PTHH: 2Al + Fe₂O₃ --t^o--> Al₂O₃ + 2Fe

Xét tỉ lệ: \(\dfrac{0,24}{2}>\dfrac{0,11}{1}\) => Hiệu suất tính theo Fe₂O₃

Gọi số mol Fe₂O₃ pư là a (mol)

PTHH: 2Al + Fe₂O₃ --t^o--> Al₂O₃ + 2Fe

           2a<-----a

=> n_{Al(sau pư)} = 0,24 - 2a (mol)

\(n_{H_2}=\dfrac{1,344}{22,4}=0,06\left(mol\right)\)

PTHH: 2KOH + 2Al + 2H₂O --> 2KAlO₂ + 3H₂

                        0,04<---------------------0,06

=> 0,24 - 2a = 0,04

=> a = 0,1 (mol)

=> \(H\%=\dfrac{0,1}{0,11}.100\%=90,9\%\)

=> B

50. The students in class are eager to take part in the Sports Day.

42 lived here for 10 years

43 you work hard, you will be sacked

44 owner of this house

45 different from mine

X

1 It is famous for its long teaching history

2 in 1070

3  No, they didn't

4 It closed in 1802

5 Yes, they can

42. I have lived here for ten years.

43. Unless you work hard, you will be sacked.

44. Mr. Hung is the owner of this house.

45. Her bag is different from mine.

46. It is famous for its long teaching history.

47. In 1070

48. No, they didn't

49. In 1082

50. Yes, they can

50c

54a

55a

Câu 49 D(đa chức chứa nhóm OH liền kế)

Câu 50 C

Câu 51 C

Câu 52 D

Câu 53 D

Câu 54 A

Câu 55 B

Câu 56 C

Câu 57 B

47 D

48 B

49 A

50 A

47 d

48 b

49 a

50 a

đây là theo suy nghĩ của mình thôi nên ko chắc nhé

49. When do you go out with your friends?

50. How often do you ride your bike?

when do you go out with your friends?

how often do you ride your bike?

49. When do you go out with your friends?

50. How often do you ride your bike?

đề đâu ạ