Substance A is a nonpolar liquid and has only dispersion forces among its constituent particles. Substance B is also a nonpolar liquid and has about the same magnitude of dispersion forces among its constituent particles as substance A. When substance A and substance B are combined, they spontaneously mix.

a. Why do the two substances mix?

b. Predict the sign and magnitude of Δ_Hsoln.

c. Determine the signs and relative magnitudes of Δ_Hsolute, Δ_Hsolvent, and Δ_Hmix.