\(n_{C_2H_2}=a\left(mol\right),n_{CH_4}=b\left(mol\right)\)
\(\Rightarrow a+b=0.2\left(1\right)\)
\(n_{CO_2}=\dfrac{13.2}{44}=0.3\left(mol\right)\)
\(\Rightarrow2a+b=0.3\left(2\right)\)
\(\left(1\right),\left(2\right):a=b=0.1\)
\(m_{C_2H_2}=0.1\cdot26=2.6\left(g\right)\)
\(n_{C_2H_2} = a(mol) ; n_{CH_4} = b(mol)\\ \Rightarrow a + b = 0,2(1)\\ C_2H_2 + \dfrac{5}{2}O_2 \xrightarrow{t^o} 2CO_2 + H_2O\\ CH_4 + 2O_2 \xrightarrow{t^o} CO_2 + 2H_2O\\ n_{CO_2} = 2a + b = \dfrac{13,2}{44} = 0,3(2)\\ (1)(2)\Rightarrow a = 0,1 ; b = 0,2\\ m_{C_2H_2} = 0,1.26 = 2,6(gam)\)