Acetic acid, `(CH_(3)COOH),` has a `pK_(a)` of `4.8`. Ethanol, `(CH_(3)CH_(2)OH)` has a `pK_(a)` of `16.0` . What are the major species present, when
Acetic acid, `(CH_(3)COOH),` has a `pK_(a)` of `4.8`. Ethanol, `(CH_(3)CH_(2)OH)` has a `pK_(a)` of `16.0` . What are the major species present, when acetic and ethanol are added to water and th e pH is odjusted to `7.0`?
A. `CH_(3)H and CH_(3)CO_(2)OH`
B. `CH_(3)CH_(2)O^(-)and CH_(3)CH_(2)OH`
C. `CH_(3)COH and CH_(3)CH_(2)O^(-)`
D. `CH_(3)CO_(2)^(2)and CH_(3)CH_(2)OH`
1 Answers
Correct Answer - D
According to Henderson equation.
`pH=pK_(a)+log.(["salt"])/(["Acid"])`
`if pHgtpK_(a)rArr["Salt"]gt["acid"]`
or Comcemtration of basic part is more than acidic part while if `pHltpK_(a)`, (Acidic part ) `gt` (Basic part)
Thus, for `CH_(3)COOH "at" pH=7 " " , CH_(3)COO^(Ө)` exist more `(pK_(a)=4.8)`
`& " " "for" CH_(3)CH_(2)OH"at"pH=7 " " , CH_(3)CYH_(2)OH` exist more `(pK_(a)=16)`