Acetic acid, `(CH_3COOH)`, has a pKa, of 4.8. Ethanol `(CH_3CH_2OH)`, has a `pK_a` of 16.0. What are the major species present, when acetic acid and ethanol are added to water and the pH is adjusted to 7.0 ?

Options

A. `CH_(3)CO_(2) H and CH_3CO_(2)OH`
B. `CH_(3)CH_(2) O^(-) and CH_3CO_(2)OH`
C. `CH_(3)CO_(2) H and CH_3CH_(2)O^(-)`
D. `CH_3CO_2^(-) and CH_3CH_2OH`

Answer

D

Explanation

pH = `pK_(a) + log (["salt"])/(["Acid"])`
If `pH gt pK_a implies ["salt"] gt ["acid"]`
or Concentration of basic part is more than acidic part while if pH `ltpK_a` (Acidic part) > (Basic part).
Thus, for `CH_3COOH` at `pH=7" , "CH_3"COO"^(Theta)` exist more `(pK_ a = 4.8) `
& for `CH_3CH_2OH` at pH = 7 `" , "CH_3CH_2OH` exist more `(pK_a =16)`