Question

Considering the energetics of transferring nonpolar molecules from water to a nonpolar solvent, the factor TS is generally _____, causing G to be _____.

a) Positive; positive
b) Negative; positive
c) Positive; negative
d) Negative; negative

Answer 1

The factor TΔS is negative, and this leads to a negative ΔG when transferring nonpolar molecules from water to a nonpolar solvent, indicating a spontaneous process due to increased entropy. Therefore, correct option is d.

Step-by-step explanation:

Considering the energetics of transferring nonpolar molecules from water to a nonpolar solvent, the factor TΔS is generally negative, causing ΔG to be negative.

The rationale for this is that when a nonpolar molecule is transferred from water, where it's unfavorably ordered due to the hydrophobic effect, to a nonpolar solvent, the entropy of the system increases as the nonpolar molecules can interact more freely.

This increased disorder (positive ΔS) actually leads to a negative value for the TΔS term because the process is exothermic (entropy increases). Since ΔG = ΔH - TΔS and T is always positive because it is measured in Kelvin, a negative TΔS makes the ΔG more negative, thus making the transfer spontaneous.