Answer
Yield $=74.65\%$
Work Step by Step
Theoretically, the mass of $SO_{2}$ that could be obtained by the reaction of $85.9mg$ of $CS_{2}$ with oxygen is equal to:
$m(SO_{2}) = m(CS_{2}) \times \frac{2\times Mr(SO_{2})}{Mr(CS_{2})}=85.9mg \times \frac{2\times 64}{76}=144.67mg$
Hence, the yield can be calculated by dividing the actual mass of $SO_{2}$ obtained by the theoretical mass:
$\alpha = \frac{108mg}{144.67mg}=74.65\%$
