Fundamentals of Organic ChemistryChemistryCarboxylic Acid Derivatives
Choose the correct statement regarding the acidic character of acetic acid ( CH ₃ COOH ) and peroxyacetic acid ( CH ₃ COOOH ).
Options
- APeroxyacetic acid is a weaker acid than acetic acid because its conjugate base is less stable than the acetate
- BPeroxyacetic acid is a stronger acid than acetic acid because it contains an additional electronegative oxygen
- CPeroxyacetic acid is a stronger acid than acetic acid because its conjugate base is a weaker base than the ace
- DBoth acids are equally strong.
Correct answer
A. Peroxyacetic acid is a weaker acid than acetic acid because its conjugate base is less stable than the acetate
Step-by-step solution
The acidic strength of an acid depends on the stability of its conjugate base. When acetic acid ( CH ₃ COOH ) loses a proton, it forms the acetate ion ( CH ₃ COO ⁻ ). The negative charge on the acetate ion is highly stabilized by resonance, as it is delocalized equally over two electronegative oxygen atoms. When peroxyacetic acid ( CH ₃ COOOH ) loses a proton, it forms the peroxyacetate ion ( CH ₃ COOO ⁻ ). In this ion, the negative charge is localized on the terminal oxygen atom. It cannot be delocalized via reson