In what form will a carboxylic acid be present in a solution of pH less than 2.0? A) predominantly as RCOO⁻ B) predominantly as RCOOH C) equal amounts of RCOOH and RCOO⁻ D) predominantly as RCO⁻

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Quizplus · Accepted Answer

Carboxylic acids will be present predominantly as their acidic form (RCOOH) at a pH less than their pKa (usually around 4-5 for carboxylic acids). At pH less than 2, the solution is very acidic and the carboxylic acid will exist completely in its acidic form. The other options are less likely because the carboxylate anion (RCOO⁻) is more stable at higher pH values and the thioester (RCO⁻) is not a common form for carboxylic acids to exist in solution.

In What Form Will a Carboxylic Acid Be Present in a Solution