Bài 25: Ankan

- C₅H₁₂:

\(CH_3-CH_2-CH_2-CH_2-CH_3:\) n-pentan

\(CH_3-CH\left(CH_3\right)-CH_2-CH_3:\) 2-metylbutan

\(CH_3-C\left(CH_3\right)_2-CH_3:\) 2,2-đimetylpropan

- C₆H₁₄:

\(CH_3-CH_2-CH_2-CH_2-CH_2-CH_3:\) n-hexan

\(CH_3-CH\left(CH_3\right)-CH_2-CH_2-CH_3:\) 2-metylpentan

\(CH_3-CH_2-CH\left(CH_3\right)-CH_2-CH_3:\) 3-metylpentan

\(CH_3-CH\left(CH_3\right)-CH\left(CH_3\right)-CH_3:\) 2,3-đimetylbutan

- C₇H₁₆:

\(CH_3-CH_2-CH_2-CH_2-CH_2-CH_2-CH_3:\) n-heptan

\(CH_3-CH\left(CH_3\right)-CH_2-CH_2-CH_2-CH_3:\) 2-metylhexan

\(CH_3-CH_2-CH\left(CH_3\right)-CH_2-CH_2-CH_3:\) 3-metylhexan

\(CH_3-CH\left(CH_3\right)-CH\left(CH_3\right)-CH_2-CH_3:\) 2,3-đimetylpentan

\(CH_3-CH\left(CH_3\right)-CH_2-CH\left(CH_3\right)-CH_3:\) 2,4-đimetylpentan

\(CH_3-C\left(CH_3\right)_2-CH_2-CH_2-CH_3:\) 2,2-đimetylpentan

\(CH_3-CH_2-C\left(CH_3\right)_2-CH_2-CH_3:\) 3,3-đimetylpentan

\(CH_3-CH_2-CH\left(C_2H_5\right)-CH_2-CH_3:\) 3-etylpentan

\(CH_3-C\left(CH_3\right)_2-CH\left(CH_3\right)-CH_3:\) 2,2,3-trimetylbutan

a, Ta có: \(n_{CO_2}=\dfrac{8,96}{22,4}=0,4\left(mol\right)=n_C\)

\(n_{H_2O}=\dfrac{10,8}{18}=0,6\left(mol\right)\Rightarrow n_H=0,6.2=1,2\left(mol\right)\)

m = m_C + m_H = 0,4.12 + 1,2.1 = 6 (g)

b, Theo ĐLBT KL, có: m + m_O2 = m_CO2 + m_H2O

⇒ m_O2 = 22,4 (g) \(\Rightarrow n_{O_2}=\dfrac{22,4}{32}=0,7\left(mol\right)\)

\(\Rightarrow V_{O_2}=0,7.22,4=15,68\left(g\right)\)

\(\Rightarrow V_{kk}=\dfrac{15,68}{20\%}=78,4\left(g\right)\)

\(n_{CO_2}=\dfrac{22,4}{22,4}=1\left(mol\right)\)

\(n_{H_2O}=\dfrac{25,2}{18}=1,4\left(mol\right)\)

Vì \(n_{H_2O}>n_{CO_2}\) => 2 hidrocacbon thuộc dãy đồng đẳng ankan.

=> \(\overline{n}_{2.hidrocacbon}=1,4-1=0,4\left(mol\right)\)

Gọi CTTQ của 2 hidrocacbon là \(C_{\overline{n}}H_{2\overline{n}+2}\)

PTHH:

\(C_nH_{2n+2}+\left(\dfrac{3n+1}{2}\right)O_2\underrightarrow{t^o}nCO_2+\left(n+1\right)H_2O\) (thêm dấu gạch ngang trên n nhé)

0,4                                       0,4n           

có:

\(0,4n=1\)

=> n = 2,5

CTPT của 2 hidrocac bon là: \(C_2H_6,C_3H_8\)

Gọi x,y lần lượt là số mol của \(C_2H_6,C_3H_8\)

\(C_2H_6+\dfrac{7}{2}O_2\underrightarrow{t^o}2CO_2+3H_2O\)

x                       2x              3x

\(C_3H_8+5O_2\underrightarrow{t^o}3CO_2+4H_2O\)

y                        3y          4y

Ta có hệ pt:

\(\left\{{}\begin{matrix}2x+3y=1\\3x+4y=1,4\end{matrix}\right.\)

=> x = 0,2 ; y = 0,2

=> \(\%_{m_{C_2H_6}}=\dfrac{0,2.30.100}{0,2.30+0,2.44}=40,54\%\)

\(\%_{m_{C_3H_8}}=100-40,54=59,46\%\)

\(n_{CO_2}=1\left(mol\right)\)

\(n_{H_2O}=1,4\left(mol\right)\)

Do \(n_{H_2O}>n_{CO_2}\) => Ankan (Bonus: 2 hđr đồng đẳng)

\(C_nH_{n+2}+\left(\dfrac{3n+1}{2}\right)O_2\rightarrow nCO_2+\left(n+1\right)H_2O\)

Đặt vào pt ta có:

\(\Rightarrow\dfrac{1}{n}=\dfrac{1,4}{n+1}\Rightarrow n=2,5\Rightarrow\left\{{}\begin{matrix}C_2H_6:x\\C_3H_8:y\end{matrix}\right.\)

Ta có hệ pt: \(\left\{{}\begin{matrix}2x+3y=1\\x+y=1,4-1\end{matrix}\right.\Rightarrow\left\{{}\begin{matrix}x=0,2\\y=0,2\end{matrix}\right.\Rightarrow\left\{{}\begin{matrix}\%m_{C_2H_6}=50\%\\\%m_{C_3H_8}=50\%\end{matrix}\right.\)

C₅H₁₁Cl:

(1) \(CH_2Cl-CH_2-CH_2-CH_2-CH_3:\) 1-clopentan

(2) \(CH_3-CHCl-CH_2-CH_2-CH_3:\) 2-clopentan

(3) \(CH_3-CH_2-CHCl-CH_2-CH_3:\) 3-clopentan

(4) \(CH_2Cl-CH\left(CH_3\right)-CH_2-CH_3:\) 1-clo-2-metylbutan

(5) \(CH_2Cl-CH_2-CH\left(CH_3\right)-CH_3:\) 2-clo-3-metylbutan

(6) \(CH_3-CCl\left(CH_3\right)-CH_2-CH_3:\) 2-clo-2-metylbutan

(7) \(CH_3-CH_2Cl-CH\left(CH_3\right)-CH_3:\) 2-clo-3-metylbutan

(8) \(CH_3-C\left(CH_3\right)_2-CH_2Cl:\) 1-clo-2,2-đimetylbutan

C₄H₈Cl₂:

(1) \(CHCl_2-CH_2-CH_2-CH_3:\) 1,1-điclobutan

(2) \(CH_2Cl-CHCl-CH_2-CH_3:\) 1,2-điclobutan

(3) \(CH_2Cl-CH_2-CHCl-CH_3:\) 1,3-điclobutan

(4) \(CH_2Cl-CH_2-CH_2-CH_2Cl:\) 1,4-điclobutan

(5) \(CH_3-CCl_2-CH_2-CH_3:\) 2,2-điclobutan

(6) \(CH_3-CHCl-CHCl-CH_3:\) 2,3-điclobutan

(7) \(CHCl_2-CH\left(CH_3\right)-CH_3:\) 1,1-điclo-2-metylpropan

(8) \(CH_2Cl-CCl\left(CH_3\right)-CH_3:\) 1,2-điclo-2-metylpropan

(9) \(CH_2Cl-CH\left(CH_3\right)-CH_2Cl:\) 1,3-điclo-2-metylpropan

C₄H₈ClBr:

(1) \(CHClBr-CH_2-CH_2-CH_3:\) 1-brom-1-clobutan

(2) \(CH_2Br-CHCl-CH_2-CH_3:\) 1-brom-2-clobutan

(3) \(CH_2Br-CH_2-CHCl-CH_3:\) 1-brom-3-clobutan

(4) \(CH_2Br-CH_2-CH_2-CH_2Cl:\) 1-brom-4-clobutan

(5) \(CH_2Cl-CHBr-CH_2-CH_3:\) 2-brom-1-clobutan

(6) \(CH_3-CClBr-CH_2-CH_3:\) 2-brom-2-clobutan

(7) \(CH_3-CHBr-CHCl-CH_3:\) 2-brom-3-clobutan

(8) \(CH_3-CHBr-CH_2-CH_2Cl:\) 3-brom-1-clobutan

(9)  \(CHClBr-CH\left(CH_3\right)-CH_3:\) 1-brom-1-clo-2-metylpropan

(10) \(CH_2Br-CCl\left(CH_3\right)-CH_3:\) 1-brom-2-clo-2-metylpropan

(11) \(CH_2Br-CH\left(CH_3\right)-CH_2Cl:\) 1-brom-3-clo-2-metylpropan

(12) \(CH_2Cl-CBr\left(CH_3\right)-CH_3:\) 2-brom-1-clo-2-metylpropan

1: \(C_{10}H_{22}\)

2: Gọi CTPT là \(C_nH_{2n+2}\)

Theo đề, ta có:

\(\dfrac{12n}{12n+2n+2}=\dfrac{4}{5}\)

=>60n=4(14n+2)

=>60n=56n+8

=>4n=8

=>n=2

=>C2H6

3: \(C_nH_{2n+2}\)

Theo đề, ta có: 12n+2n+2=44

=>14n=42

=>n=3

=>C3H8

⇒ Tên gọi: 1-Brom-2-clo-3-metylpentan

⇒ Tên gọi: 2,2-Điclo-3-etylpentan