Câu 28:

\(n_{hh.khí}=\dfrac{2,24}{22,4}=0,1\left(mol\right)\)

=> \(\left\{{}\begin{matrix}n_{C_2H_2}=\dfrac{2}{2+3}.0,1=0,04\left(mol\right)\\n_{H_2}=0,1-0,04=0,06\left(mol\right)\end{matrix}\right.\)

\(n_Z=\dfrac{0,896}{22,4}=0,04\left(mol\right)\)

Sơ đồ phản ứng:

\(X\left\{{}\begin{matrix}C_2H_2:0,04\text{ }mol\\H_2:0,06\text{ }mol\end{matrix}\right.\xrightarrow[t^o]{Ni}Y\left\{{}\begin{matrix}H_2\\C_2H_2\\C_2H_4\\C_2H_6\end{matrix}\right.\xrightarrow[]{+Br_2}0,04\text{ }mol\text{ }Z\left\{{}\begin{matrix}H_2\\C_2H_6\end{matrix}\right.\)

Ta có: \(M_Z=4,5.2=9\left(g/mol\right)\)

=> m_Z = 9.0,04 = 0,36 (g)

Theo ĐLBTKL: m_Y = m_X = 0,04.26 + 0,06.2 = 1,16 (g)

Ta có: \(m_{C_2H_2\left(pư\right)}+m_{C_2H_4\left(pư\right)}=m_Y-m_Z=1,16-0,36=0,8\left(g\right)\)

Mà \(m_{tăng}=m_{C_2H_2\left(pư\right)}+m_{C_2H_4\left(pư\right)}\) => m_tăng = 0,8 (g)

=> Chọn B

Câu 27:

Gọi \(\left\{{}\begin{matrix}n_{C_2H_2\left(dư\right)}=a\left(mol\right)\\n_{C_4H_4\left(dư\right)}=b\left(mol\right)\end{matrix}\right.\)

\(n_{Br_2}=0,05.1=0,05\left(mol\right)\)

Gọi \(\left\{{}\begin{matrix}n_{C_2H_2\left(dư\right)}=a\left(mol\right)\\n_{C_4H_4\left(dư\right)}=b\left(mol\right)\end{matrix}\right.\)

=> \(n_{\pi\left(dư\right)}=2a+3b\left(mol\right)\)

\(\text{BTLK }\pi:2n_{C_2H_2}+3n_{C_4H_4}=n_{H_2}+n_{Br_2}+n_{\pi\left(dư\right)}\)

=> 2a + 3b = 2.0,06 + 3.0,09 - 0,16 - 0,05 = 0,18 (*)

\(n_{khí.Z}=\dfrac{1,792}{22,4}=0,08\left(mol\right)\)

Theo ĐLBTKL: 

\(m_Y=m_X=0,06.26+0,09.52+0,16.2=6,56\left(g\right)\)

Ta có: \(M_Y=\dfrac{328}{15}.2=\dfrac{656}{15}\left(g/mol\right)\)

=> \(n_Y=\dfrac{6,56}{\dfrac{656}{15}}=0,15\left(mol\right)\)

Lại có: \(n_{C_2H_2\left(dư\right)}+n_{C_4H_4\left(dư\right)}=n_Y-n_Z=0,15-0,08=0,07\left(mol\right)\)

=> a + b = 0,07 (**)

Từ (*), (**) => a = 0,03; b = 0,04

PTHH:
\(C_2H_2\xrightarrow[]{+AgNO_3/NH_3}C_2Ag_2\downarrow\)

0,03----------------->0,03

\(C_4H_4\xrightarrow[]{+AgNO_3/NH_3}C_4H_3Ag\downarrow\)

0,04------------------>0,04

=> m = 0,03.240 + 0,04.159 = 13,56 (g)

=> Chọn C

II. Choose the underlined part that needs correcting in each sentence below

21. Nancy was refused (A) to be given (B) a scholarship to study (C) abroad two days ago. She could have (D) been very sad.

22. There is (A) no parking sign here so (B) you would better (C) take your car out of (D) here you now

23. If (A) you are (B) free day today, you will join (C) our party at (D) the club

24. The company is going to (A) held (B) a party to celebrate (C) the establishment (D) 

25. The manager would dismiss (A) his secretary if (B) the secretary makes such (C) stupid mistakes in (D) the the reports.

a) \(4NH_3+5O_2\xrightarrow[Pt]{t^o}4NO\uparrow+6H_2O\)

b) \(4Mg+10HNO_3\rightarrow4Mg\left(NO_3\right)_2+NH_4NO_3+3H_2O\)

c) \(4Zn+5H_2SO_{4\left(đặc,nóng\right)}\rightarrow4ZnSO_4+H_2S\uparrow+4H_2O\)

d) \(MnO_2+4HCl\rightarrow MnCl_2+Cl_2\uparrow+2H_2O\)

e) \(2KMnO_4+16HCl\rightarrow2KCl+2MnCl_2+5Cl_2\uparrow+8H_2O\)

f) \(2KMnO_4+10FeSO_4+8H_2SO_4\rightarrow K_2SO_4+MnSO_4+5Fe_2\left(SO_4\right)_3+8H_2O\)

g) \(2KMnO_4+3K_2SO_3+H_2O\rightarrow2KOH+2MnO_2\downarrow+3K_2SO_4\)

h) \(8FeO+26HNO_3\rightarrow8Fe\left(NO_3\right)_3+N_2O\uparrow+13H_2O\)

Cần kèm lời giải thích nữa ạ

6. What would you do if you _____ a million pounds?

A. win

B. won

C. will win

D. A and C

7. If it _____, we will go to the movies.

A. didn't rain 

B. doesn't rain

C. won't rain

D. isn't rain

8. If you _____ here yesterday, you _____ me.

A. were/would meet

B. had been/ woulld meet

C. were/would have met

D. had been/ would have met

9. If I was offerred the job, I think I _____ it.

A. take

B. will take

C. would take

D. would have take

10. I would be very surprised if he _____

A. refuse

B. refused

C. had refuse

D. would refuse

*Có kèm lời giải thích ạ

I. Choose the best option A, B, C or D to complete the sentences.

1. If I _____ get a pole, I'll go fishing.

A. can

B. could

C. may

D. might

2. If you had had the chance, _____ you go fishing?

A. did

B. may

C. would

D. do

3. If you _____ a choice, which country would you visit?

A. have

B. had

C. have had

4. If rains tomorrow, we _____ the trip

A. will cancel

B. would cancel

C. cancelled

D. have cancelled

5. I don't really want to go to their party, but probably will go. They'd be offended if I _____ go.

A. didn't

B. don't

C. will

D. will not

19. \(BaO+SO_3\rightarrow BaSO_4\)

20. \(3K_2O+P_2O_5\rightarrow2K_3PO_4\)

21. \(3CaO+P_2O_5\rightarrow Ca_3\left(PO_4\right)_2\)

22. \(K_2O+N_2O_5\rightarrow2KNO_3\)

23. \(BaO+N_2O_5\rightarrow Ba\left(NO_3\right)_2\)

24. \(Na_2O+2HCl\rightarrow2NaCl+H_2O\)

25. \(CaO+2HCl\rightarrow CaCl_2+H_2O\)

26. \(Al_2O_3+6HCl\rightarrow2AlCl_3+3H_2O\)

27. \(K_2O+H_2SO_4\rightarrow K_2SO_4+H_2O\)

28. \(BaO+H_2SO_4\rightarrow BaSO_4\downarrow+H_2O\)

29. \(Fe_2O_3+3H_2SO_4\rightarrow Fe_2\left(SO_4\right)_3+3H_2O\)

30. \(K_2O+2HNO_3\rightarrow2KNO_3+H_2O\)

31. \(ZnO+2HNO_3\rightarrow Zn\left(NO_3\right)_2+H_2O\)

32. \(Fe_2O_3+6HNO_3\rightarrow2Fe\left(NO_3\right)_3+3H_2O\)

33. \(3Na_2O+2H_3PO_4\rightarrow2Na_3PO_4\)

34. \(3MgO+2H_3PO_4\rightarrow Mg_3\left(PO_4\right)_2\downarrow+3H_2O\)

35. \(Al_2O_3+2H_3PO_4\rightarrow2AlPO_4\downarrow+3H_2O\)

36. \(Fe_3O_4+8HCl\rightarrow FeCl_2+2FeCl_3+4H_2O\)

37. \(Fe_3O_4+4H_2SO_4\rightarrow FeSO_4+Fe_2\left(SO_4\right)_3+4H_2O\)

38. \(3Fe_3O_4+8H_3PO_4\rightarrow Fe_3\left(PO_4\right)_2\downarrow+6FePO_4\downarrow+12H_2O\)

39. \(CO_2+2NaOH\rightarrow Na_2CO_3+H_2O\)

40. \(CO_2+Ca\left(OH\right)_2\rightarrow CaCO_3\downarrow+H_2O\)

41. \(SO_2+2KOH\rightarrow K_2SO_3+H_2O\)

42. \(SO_2+Ba\left(OH\right)_2\rightarrow BaSO_3\downarrow+H_2O\)

43. \(SO_3+2NaOH\rightarrow Na_2SO_4+H_2O\)

44. \(SO_3+Ba\left(OH\right)_2\rightarrow BaSO_4\downarrow+H_2O\)

45. \(N_2O_5+2KOH\rightarrow2KNO_3+H_2O\)

46. \(N_2O_5+Ca\left(OH\right)_2\rightarrow Ca\left(NO_3\right)_2+H_2O\)

47. \(P_2O_5+6NaOH\rightarrow2Na_3PO_4+3H_2O\)

48. \(P_2O_5+3Ba\left(OH\right)_2\rightarrow Ba_3\left(PO_4\right)_2\downarrow+3H_2O\)