Gọi \(\left\{{}\begin{matrix}n_{C_2H_2}=a\left(mol\right)\\n_{C_3H_6}=b\left(mol\right)\\n_{C_2H_6}=c\left(mol\right)\end{matrix}\right.\) => 26a + 42b + 30c = 20,4 (1)
Ta có: \(n_{kk}=\dfrac{253,2}{22,4}=10,5\left(mol\right)\Rightarrow n_{O_2}=\dfrac{10,5}{5}=2,1\left(mol\right)\)
PTHH:
2C2H2 + 5O2 --to--> 4CO2 + 2H2O
a-------->2,5a
2C3H6 + 9O2 --to--> 6CO2 + 6H2O
b------->4,5b
2C2H6 + 7O2 --to--> 4CO2 + 6H2O
c------->3,5c
=> 2,5a + 4,5b + 3,5c = 2,1 (2)
- Mặt khác: Gọi \(\left(n_{C_2H_2};n_{C_3H_6};n_{C_2H_6}\right)=\left(ak;bk;ck\right)\left(mol\right)\)
\(n_{khí}=\dfrac{12,544}{22,4}=0,56\left(mol\right)\)
=> ak + bk + ck = 0,56 (3)
Ta có: Vkhí giảm = VH2 (pư) => \(n_{H_2\left(pư\right)}=\dfrac{17,92}{22,4}=0,8\left(mol\right)\)
PTHH:
\(C_2H_2+2H_2\xrightarrow[t^o]{Ni}C_2H_6\)
ak----->2ak
\(C_3H_6+H_2\xrightarrow[]{t^o}C_3H_8\)
bk----->bk
=> 2ak + bk = 0,8 (4)
Từ (1), (2), (3), (4) => \(\left\{{}\begin{matrix}a=0,45\\b=0,1\\c=0,15\\k=1,25\end{matrix}\right.\)
=> \(\left\{{}\begin{matrix}\%V_{C_2H_2}=\dfrac{0,45}{0,45+0,1+0,15}.100\%=64,3\%\\\%V_{C_3H_6}=\dfrac{0,1}{0,45+0,1+0,15}.100\%=14,3\%\\\%V_{C_2H_6}=\left(100-64,3-14,3\right)\%=21,4\%\end{matrix}\right.\)
