\(n_{SO_2}=\dfrac{6,72}{22,4}=0,3\left(mol\right)\)
\(n_{O_2}=\dfrac{8}{32}=0,25\left(mol\right)\)
\(n_{CH_4}=\dfrac{6\times10^{22}}{6\times10^{23}}=0,1\left(mol\right)\)
\(\Rightarrow V_{hh}=\left(0,3+0,25+0,1+0,2\right)\times22,4=19,04\left(l\right)\)
\(m_{Cl_2}=0,2\times71=11,2\left(g\right)\)
\(m_{SO_2}=0,3\times64=19,2\left(g\right)\)
\(m_{CH_4}=0,1\times16=1,6\left(g\right)\)
\(\Rightarrow m_{hh}=11,2+8+19,2+1,6=40\left(g\right)\)