Câu 23:

Ta có: n_H2O - n_CO2 = n_A = 0,23 - 0,14 = 0,09 (mol)

\(\Rightarrow\left\{{}\begin{matrix}\%n_A=\dfrac{0,09}{0,1}.100\%=90\%\\\%n_B=10\%\end{matrix}\right.\)

→ Đáp án: A

Câu 24: 

n_CO2 = n_H2O ⇒ X là anken.

→ Đáp án: D

23) 

BTNT C: \(n_C=n_{CO_2}=n_{BaCO_3}=\dfrac{39,4}{197}=0,2\left(mol\right)\)

Ta có: \(\Delta m_{\downarrow}=m_{BaCO_3}-m_{CO_2}-m_{H_2O}\)

\(\Rightarrow m_{H_2O}=39,4-0,2.44-26,1=4,5\left(g\right)\\ \Rightarrow n_{H_2O}=\dfrac{4,5}{18}=0,25\left(mol\right)\)

Ta có: \(n_{H_2O}>n_{CO_2}\Rightarrow\) X thuộc dãy đồng đẳng ankan

\(\Rightarrow n_X=n_{H_2O}-n_{CO_2}=0,05\left(mol\right)\)

BTNT H: \(n_H=2n_{H_2O}=0,5\left(mol\right)\)

\(\Rightarrow m_X=0,5+0,2.12=2,9\left(g\right)\\ \Rightarrow M_X=\dfrac{2,9}{0,05}=58\left(g/mol\right)\)

Đặt CTPT của X là C_nH_2n+2

=> 14n + 2 = 58 => n = 4

Vậy X là C₄H₁₀

Chọn B

Câu 23:

BTNT C, có: \(3n_{C_3H_4}+2n_{C_2H_4}+n_{CH_4}=n_{CO_2}=1,08\left(1\right)\)

\(n_{Br_2}=2n_{C_3H_4}+n_{C_2H_4}=\dfrac{76,8}{160}=0,48\left(mol\right)\left(2\right)\)

\(n_{C_3H_4}=n_{C_3H_3Ag}=\dfrac{26,46}{135}=0,196\left(mol\right)\left(3\right)\)

Từ (1), (2) và (3) \(\Rightarrow\left\{{}\begin{matrix}n_{C_3H_4}=0,196\left(mol\right)\\n_{C_2H_4}=0,088\left(mol\right)\\n_{CH_4}=0,316\left(mol\right)\end{matrix}\right.\)

⇒ m = 15,36 (g)

→ Đáp án: C

Câu 22: B

Câu 23: CTPT của Y là C_nH_2n+2.

→ CTPT của dẫn xuất monobrom là: C_nH_2n+1Br.

\(\Rightarrow M_{C_nH_{2n+1}Br}=61,5.2=123\left(g/mol\right)\)

\(\Rightarrow12n+2n+1+80=123\Rightarrow n=3\)

Vậy: Y là C₃H₈.

→ Đáp án: B

23D

24A

25C

26C

27D

29D

Câu 20:
X: \(C_nH_{2n+2}O\)

Theo đề, ta có: \(\dfrac{16}{12n+2n+2+16}=21.62\%\)

=>14n+18=74

=>14n=56

=>n=4

=>\(C_4H_{10}O\)

=>Chọn D

Câu 21:

\(C_nH_{2n-2}+AgNO_3+NH_3\rightarrow C_nH_{2n-3}Ag+NH_4NO_3\\ n_X=\dfrac{14-5,44}{108-1}=0,08\left(mol\right)=n_{kết.tủa}\\ M_{C_nH_{2n-3}Ag}=\dfrac{14}{0,08}=175\left(\dfrac{g}{mol}\right)=14n+107\\ \Leftrightarrow n=5\\ \Rightarrow CTPT.X:C_5H_8\\ CTCT:CH\equiv C-CH_2-CH_2-CH_3\\ CH_3-C\equiv C-CH_2-CH_3\\ CH\equiv C-CH\left(CH_3\right)-CH_3\)

Chọn C

Câu 22: 

\(n_{C_2H_2}=\dfrac{2,24}{22,4}=0,1\left(mol\right)\\ C_2H_2+2Br_2\rightarrow C_2H_2Br_4\\ n_{Br_2}=2.n_{C_2H_2}=2.0,1=0,2\left(mol\right)\\ m_{Br_2}=0,2.160=32\left(g\right)\\ Chọn.A\)

Câu 23:

\( PTHH:C_2H_2+2Br_2\rightarrow C_2H_2Br_4\left(1\right)\\ C_2H_4+Br_2\rightarrow C_2H_4Br_2\left(2\right)\\ C_2H_2+2AgNO_3+2NH_3\rightarrow Ag_2C_2+2NH_4NO_3\\ n_{Ag_2C_2}=\dfrac{18}{240}=0,075=n_{C_2H_2}\\ n_{Br_2\left(tổng\right)}=\dfrac{40}{160}=0,25\left(mol\right)\\ n_{Br_2\left(1\right)}=2.n_{C_2H_2}=2.0,075=0,15\left(mol\right)\\ n_{Br_2\left(2\right)}=0,25-0,15=0,1\left(mol\right)\\ V=V_{C_2H_2\left(đktc\right)}+V_{C_2H_4\left(đktc\right)}=0,075.22,4+0,1.22,4=3,92\left(lít\right)\\ Chọn.A\)

23 C

24 D

25 C

26 A

27 A

28 D

29 B

30 B

31 D

32 A

33 D

34 A

35 B

C D C