\(\begin{array}{l}
198)\\
C + {O_2} \to C{O_2}\\
S + {O_2} \to S{O_2}\\
n{O_2} = \frac{{3,36}}{{22,4}} = 0,15\,mol\\
C(a\,mol),S(b\,mol)\\
12a + 32b = 2,8\\
a + b = 0,15\\
= > a = 0,1\,b = 0,05\,mol\\
mC = 0,1 \times 12 = 1,2g\\
mS = 0,05 \times 32 = 1,6g\\
199)\\
2{C_2}{H_2} + 5{O_2} \to 4C{O_2} + 2{H_2}O\\
n{O_2} = \frac{{1 \times 5}}{2} = 2,5\,mol\\
V{O_2} = 2,5 \times 22,4 = 56l
\end{array}\)