Air is bubbled through a drum of liquid toluene $(C_6{H}_{5}C{H}_3)$ at a rate of $1\mathrm{.}67mo{l}^{-1}.$ The gas stream leaving the drum contains $10\mathrm{.}0$ mole$\%$ toluene vapor. Air may be considered insoluble in liquid toluene. $($Toluene has a density of $0\mathrm{.}87\frac{g}{m}L).$

Calculate the time required to vaporize ${10}^{4}L$ of the liquid.