Answer:
E
Explanation:
Recall the Henderson-Hasselbalch equation:
[tex]\displaystyle \text{pH} = \text{p}K_a + \log \frac{[\text{Base}]}{[\text{Acid}]}[/tex]
For a pH of 5.14 with the given pKa of 4.74, solve for the ratio between acetate and acetic acid:
[tex]\displaystyle \begin{aligned} (5.14) & = (4.74) + \log\frac{[\text{CH$_3$COO$^-$}]}{[\text{CH$_3$COOH}]} \\ \\ \log\frac{[\text{CH$_3$COO$^-$}]}{[\text{CH$_3$COOH}]}& = 0.40 \\ \\ \frac{[\text{CH$_3$COO$^-$}]}{[\text{CH$_3$COOH}]} & = 10^{0.40} \\ \\ & = 2.5\end{aligned}[/tex]
In conclusion, the answer is E.
