a. \(CH_4+2O_2\underrightarrow{t^o}CO_2+2H_2O\)

     a          2a      a

\(C_2H_4+3O_2\underrightarrow{t^o}2CO_2+2H_2O\)

  b          3b       2b

b. \(n_{O_2}=\dfrac{25.88}{22.4}=1.155mol\)

n hỗn hợp khí \(=\dfrac{11.2}{22.4}=0.5mol\)

Ta có: \(\left\{{}\begin{matrix}a+b=0.5\\2a+3b=1.155\end{matrix}\right.\Leftrightarrow\left\{{}\begin{matrix}a=0.345\\b=0.155\end{matrix}\right.\)

\(\%V_{CH_4}=\dfrac{0.345\times22.4\times100}{11.2}=69\%\)

\(\%V_{C_2H_4}=100-69=31\%\)

c. \(V_{CO_2}=\left(a+2b\right)\times22.4=\left(0.345+2\times0.155\right)\times22.4=14.672l\)

a, \(CH_4+2O_2\underrightarrow{^{t^o}}CO_2+2H_2O\)

\(C_2H_4+3O_2\underrightarrow{^{t^o}}2CO_2+2H_2O\)

b, Gọi: \(\left\{{}\begin{matrix}n_{CH_4}=x\left(mol\right)\\n_{C_2H_4}=y\left(mol\right)\end{matrix}\right.\) \(\Rightarrow x+y=\dfrac{4,48}{22,4}=0,2\left(mol\right)\left(1\right)\)

Theo PT: \(n_{O_2}=2n_{CH_4}+3n_{C_2H_4}=2x+3y=\dfrac{15,68}{22,4}=0,7\left(mol\right)\left(2\right)\)

Từ (1) và (2) \(\Rightarrow\left\{{}\begin{matrix}x=-0,1\\y=0,3\end{matrix}\right.\)

Đến đây thì ra số mol âm, bạn xem lại đề nhé.

a) 

\(n_{Br_2}=\dfrac{8}{160}=0,05\left(mol\right)\)

PTHH: C₂H₄ + Br₂ --> C₂H₄Br₂

             0,05<-0,05

=> \(n_{CH_4}=\dfrac{3,36}{22,4}-0,05=0,1\left(mol\right)\)

\(\%m_{CH_4}=\dfrac{0,1.16}{0,1.16+0,05.28}.100\%=53,33\%\)

\(\%m_{C_2H_4}=\dfrac{0,05.28}{0,1.16+0,05.28}.100\%=46,67\%\)

b)

PTHH: CH₄ + 2O₂ --t^o--> CO₂ + 2H₂O

            0,1-->0,2

            C₂H₄ + 3O₂ --t^o--> 2CO₂ + 2H₂O

           0,05--->0,15

=> \(V_{O_2}=\left(0,2+0,15\right).22,4=7,84\left(l\right)\)

CH₄+2O₂-to>CO₂+2H₂O

x------2x---------x

C₂H₄+3O₂-to>2CO₂+2H₂O

y----------3y--------2y

=>\(\left\{{}\begin{matrix}x+y=\dfrac{5,6}{22,4}\\2x+3y=\dfrac{13,44}{22,4}\end{matrix}\right.\)

=>x=0,15 mol , y=0,1 mol

=>%V_CH4=\(\dfrac{0,15.22,4}{5,6}\).100=60%

=>%V_C2H4=100-60=40%

b)

V_CO2=(0,15+0,1.2).22,4=7,84l

mhh khí = 5,6/22,4 = 0,25 (mol)

nO2 = 13,44/22,4 = 0,6 (mol)

Gọi nC2H4 = a (mol); nCH4 = b (mol)

a + b = 0,25 (1)

PTHH:

C2H4 + 3O2 -> (t°) 2CO2 + 2H2O

Mol: a ---> 3a ---> 2a

CH4 + 2O2 -> (t°) CO2 + 2H2O

Mol: b ---> 2b ---> b

3a + 2b = 0,6 (2)

(1)(2) => a = 0,1 (mol); b = 0,15 (mol)

%VC2H4 = 0,1/0,25 = 40%

%VCH4 = 100% - 40% = 60%

VCO2 = (0,1 . 2 + 0,15) . 22,4 = 7,84 (l)