Final answer:
Substance A and B mix due to being nonpolar liquids with similar dispersion forces, following the principle of 'like dissolves like'.
The ΔHsoln is expected to be small and close to zero because the dispersion forces are about the same in both substances.
ΔHsolute and ΔHsolvent are likely to be slightly positive, whereas ΔHmix might be slightly negative, but all are anticipated to be of small magnitude.
Step-by-step explanation:
Substance A and B mix because they are both nonpolar liquids and have similar types of intermolecular forces (dispersion forces). Such mixing is guided by the principle of 'like dissolves like', which indicates that substances with similar polarities and intermolecular forces tend to mix and form solutions.
ΔHsoln (the enthalpy change of the solution process) would likely be small and close to zero, and could be either slightly positive or negative. Given that both substances are held together by dispersion forces, and these forces are disrupted and formed again during the mixing, the energy involved in both processes is almost the same.
As for ΔHsolute, ΔHsolvent, and ΔHmix, these represent the enthalpy changes associated with the solute and the solvent separation, and the mixing process, respectively. ΔHsolute and ΔHsolvent would be positive because energy is required to overcome intermolecular forces in the pure substances, while ΔHmix might be negative as energy is released when new intermolecular forces are formed in the mixture. However, since the forces being broken and formed are similar, the values are expected to be small and of similar magnitudes.