Question

Which of the following molecular structures is LEAST likely to display surface-active properties?

A. 2 FA tails and polar head
B. Soap (FA with COO- and Na+)
C. carbon backbone with a sulfate on a benzene
D. Benzene with A sulfate and 3 NO2 groups

Answer 1

Benzene with a sulfate and 3 NO2 groups is least likely to have surface-active properties due to the lack of a balance between hydrophilic and hydrophobic regions, as the nitro groups would make the molecule more electron-withdrawing.

Step-by-step explanation:

The molecule least likely to display surface-active properties is benzene with a sulfate and 3 NO2 groups. Surface-active molecules typically have parts that are hydrophilic (water-attracting) and hydrophobic (water-repelling), allowing them to interact with both aqueous and non-aqueous phases and reduce surface tension.

A sulfate group is hydrophilic, but three nitro groups (NO2) would add substantial electron-withdrawing character, making the molecule overall less likely to interact favorably with water, thus diminishing its surface-active properties in comparison to molecules with better-balanced hydrophobic and hydrophilic regions.