Three monocarboxylic acids are listed below with their condensed structural formulas
CHEMISTRY · Multi-part · AP · Chemistry · Acids and Bases · Acids and Bases
Problem
Three monocarboxylic acids are listed below with their condensed structural formulas.
• Acetic acid: CH3COOH
• α-Chloroacetic acid: ClCH2COOH
• β-Chloropropionic acid: ClCH2CH2COOH
A student investigates how the presence and position of a chlorine atom affect the ability of each acid to donate a proton in aqueous solution.
(a) Rank the three acids from strongest to weakest and write the corresponding inequality for their Ka values.
(b) Provide a molecular-level explanation for the ranking in part (a) that refers to both the identity of the substituent and its position relative to the carboxyl group.
(c) Predict whether 4-chlorobutyric acid (ClCH2CH2CH2COOH) would be a stronger or weaker acid than acetic acid. Justify your prediction with reference to your explanation in part (b).