A mixture of benzene and toluene are to be separated in a flash tank. At what temperature

Question:

A mixture of benzene and toluene are to be separated in a flash tank. At what temperature should the tank be operated to get the highest purity toluene in the liquid phase (maximizing x_T)? The pressure in the flash tank is 800 mm Hg. The units for Antoine’s equation are mm Hg and °C for pressure and temperature, respectively.

x_BP_{sat B} + x_TP_{sat T} = P

log₁₀ (P_{sat B}) = 6.905 – 1211/T + 221

log₁₀ (P_{sat T}) = 6.953 – 1344/T + 219