$SO_{3}+H_{2}O\rightarrow H_{2}SO_{4}$a a molC%=$\frac{98a+(100-80a)\times10:100 }{100} \times 100=$20%$\Rightarrow a=\frac{1}{9}\Rightarrow m_{SO3}=8,88g$
$SOx_{3}+H_{2}O\rightarrow H_{2}SO_{4}$a a molC%=$\frac{98a+(100-80a)\times10:100 }{100} \times 100=$20%$\Rightarrow a=\frac{1}{9}\Rightarrow m_{SO3}=8,88g$
$SO_{3}+H_{2}O\rightarrow H_{2}SO_{4}$a a molC%=$\frac{98a+(100-80a)\times10:100 }{100} \times 100=$20%$\Rightarrow a=\frac{1}{9}\Rightarrow m_{SO3}=8,88g$