The pka value for the carboxylic acid group in acetic acid is 4.75. write the predominant structure of acetic acid at (a ph=1, (b ph=7

Hello!

A) At pH=1

This pH is lower than the value for the pKa, so Acetic acid wouldn't be ionized, but the equilibrium would be displaced to CH₃COOH

CH₃COOH ⇄ CH₃COO⁻ + H₃O⁺ (equilibrium displaced to the left)

The chemical structure for CH₃COOH is the first one in the attached images.

B) At pH=7

This pH is higher than the value for the pKa, so Acetic acid would be ionized, and the equilibrium would be displaced to CH₃COO⁻

CH₃COOH ⇄ CH₃COO⁻ + H₃O⁺ (equilibrium displaced to the right)

The chemical structure for CH₃COO⁻ is the second one in the attached images.

Have a nice day!