A tower packed with $25-\mathrm{mm}$ ceramic Raschig rings is to be used for absorbing benzene vapor from a dilute mixture with an inert gas using a wash oil at $300 \mathrm{~K}$.

The viscosity of the oil is $2.0 \mathrm{cP}$ and its density is $840 \mathrm{~kg} / \mathrm{m}^{3}$. The liquid mass velocity is $G_{x}=2.71 \mathrm{~kg} / \mathrm{m}^{2}$-s. Estimate the liquid holdup, the operational void fraction, and the hydraulic specific area of the packing.