Water $(60lb$ moles$),$ benzene $(20lb$ moles$),$ and toluene $(20lb$ moles$)$ equilibrate as a liquid

mixture at a pressure of $0\mathrm{.}9$atm. The water $($W$)$ and the organics are immiscible, and the

benzene $($B$)$ and the toluene $($T$)$ form an ideal mixture.

The following ratios of vapor pressures can be assumed constant over the temperature range of

interest:

$\frac{P_B}{P_W}=2\mathrm{.}11$

$\frac{P_T}{P_W}=0\mathrm{.}813$

At the bubble$-$point temperature and the specified system pressure, the saturation pressure

$(atm)$ of water, $P_w,$ is most nearly:

$($A$)0\mathrm{.}23$

$($B$)0\mathrm{.}37$

$($C$)0\mathrm{.}62$

$($D$)0\mathrm{.}76$