Question #44519

At 298 K, 37.0 g of 1-chlorobutane (Molar mass = 92.5 g/mol) is mixed with 36.9 g of anhydrous tetrabutylammonium iodide (TBAI, Molar mass = 369 g/mol). The system undergoes an in-situ Finkelstein-type exchange:

$\ce{C4H9Cl(l) + TBAI(solv) <=> C4H9I(l) + TBACl(solv)}$

The equilibrium constant for this reaction at 298 K is $K_c = 1.0$. Unlike the classic Finkelstein reaction, all ammonium salts remain completely dissolved as non-volatile, undissociated ion pairs in the homogeneous liquid phase. Assuming the final liquid mixture of haloalkanes behaves as an ideal solution, what is the total vapor pressure of the system at equilibrium?

(Given at 298 K: $P^\circ_{\ce{C4H9Cl}} = 100$ Torr, $P^\circ_{\ce{C4H9I}} = 30$ Torr)