\(n_{O_2}=\dfrac{15}{32}=0.46875\left(mol\right)\)
\(n_{SO_2}=\dfrac{19.2}{64}=0.3\left(mol\right)\)
\(S+O_2\underrightarrow{t^0}SO_2\)
\(0.3...0.3....0.3\)
\(m_S=0.3\cdot32=9.6\left(g\right)\)
\(m_{O_2\left(dư\right)}=\left(0.46875-0.3\right)\cdot32=5.4\left(g\right)\)